2015-05-28  Richard Biener  <rguenther@suse.de>

	* tree-vect-loop.c (vect_fixup_reduc_chain): New function.
	(vect_fixup_scalar_cycles_with_patterns): Likewise.
	(vect_analyze_loop_2): Call vect_fixup_scalar_cycles_with_patterns
	after pattern recog.
	(vect_create_epilog_for_reduction): Properly handle reductions
	with patterns.
	(vectorizable_reduction): Likewise.
	* tree-vect-slp.c (vect_analyze_slp_instance): Properly mark
	reduction chains.
	(vect_get_constant_vectors): Create the correct number of
	initial values for reductions.
	(vect_schedule_slp_instance): Handle reduction chains that are
	type changing properly.
	* tree-vect-stmts.c (vect_analyze_stmt): Adjust.

	* gcc.dg/vect/slp-reduc-sad.c: New testcase.

From-SVN: r223818

2015-05-28  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch3.adb (Is_Visible_Component): Component is visible
	in a derived type if inherited through an ancestor that has a
	partial view of the original type holding the component, if the
	full view of that original type is in scope.
	* sem_util.ads (Get_Body_From_Stub): Works for all kinds of stubs.

2015-05-28  Bob Duff  <duff@adacore.com>

	* sem_util.adb (Requires_Transient_Scope): For definite untagged
	subtypes, we should never have to use the secondary stack. This moves
	toward that goal. But there are still cases that don't work.
	Here, we move the check for Is_Definite first, but add a
	special-purpose check for Has_Discrim_Dep_Array.

From-SVN: r223817

re PR tree-optimization/66142 (Loop is not vectorized because not sufficient support for GOMP_SIMD_LANE)

2015-05-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66142
	* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle non-GIMPLE
	values better in memcpy destination handling.  Handle non-aliasing
	we discover here.

	* gcc.dg/tree-ssa/ssa-fre-44.c: Fixup.

From-SVN: r223816

sem_util.adb (Requires_Transient_Scope): Avoid returning function results on the secondary stack in so many cases.

2015-05-28  Bob Duff  <duff@adacore.com>

	* sem_util.adb (Requires_Transient_Scope): Avoid returning
	function results on the secondary stack in so many cases.

From-SVN: r223814

2015-05-28  Lawrence Velázquez  <vq@larryv.me>

	PR target/63810
	* config/darwin-c.c (version_components): New global enum.
	(parse_version, version_as_legacy_macro)
	(version_as_modern_macro, macosx_version_as_macro): New functions.
	(version_as_macro): Remove.
	(darwin_cpp_builtins): Use new function.

testsuite:
	PR target/63810
	* gcc.dg/darwin-minversion-3.c: Update testcase.
	* gcc.dg/darwin-minversion-4.c: Ditto.
	* gcc.dg/darwin-minversion-5.c: New testcase.
	* gcc.dg/darwin-minversion-6.c: Ditto.
	* gcc.dg/darwin-minversion-7.c: Ditto.
	* gcc.dg/darwin-minversion-8.c: Ditto.
	* gcc.dg/darwin-minversion-9.c: Ditto.
	* gcc.dg/darwin-minversion-10.c: Ditto.
	* gcc.dg/darwin-minversion-11.c: Ditto.
	* gcc.dg/darwin-minversion-12.c: Ditto.

From-SVN: r223808

re PR libstdc++/65352 (array<T,0>::begin()/end() etc. forms a null reference and breaks on clang+ubsan)

	PR libstdc++/65352
	* include/std/array (__array_traits::_S_ptr): New function.
	(array::data): Use _S_ptr to avoid creating invalid reference.
	* testsuite/23_containers/array/tuple_interface/get_neg.cc: Adjust
	dg-error line numbers.
	* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
	likewise.

From-SVN: r223806

	* builtins.c (expand_builtin_acc_on_device): Mark parameters
	with ATTRIBUTE_UNUSED.

From-SVN: r223805

2015-05-28  Ed Schonberg  <schonberg@adacore.com>

	* sem_util.adb (Wrong_Type): In any instance, do not emit error
	if type of expression is the partial view of the expected type.

2015-05-28  Ed Schonberg  <schonberg@adacore.com>

	* sem_res.adb (Resolve_Actuals): a)  The replacement of formal
	names in named associations only needs to be done within an
	instance, on a call to a primitive of a formal derived type,
	where the actual subprogram may have different formal names than
	those of the primitive operation of the formal type.
	b) Defaulted parameters must be taken into account when obtaining
	the names of the formals of the actual subprogram being called.

From-SVN: r223804

	* oacc-init.c (resolve_device): Add FAIL_IS_ERROR argument. Update
	function comment. Only call gomp_fatal if new argument is true.
	(acc_dev_num_out_of_range): New function.
	(acc_init_1, acc_shutdown_1): Update call to resolve_device. Call
	acc_dev_num_out_of_range as appropriate.
	(acc_get_num_devices, acc_set_device_type, acc_get_device_type)
	(acc_get_device_num, acc_set_device_num): Update calls to resolve_device.
	* testsuite/libgomp.oacc-c-c++-common/lib-4.c: Update expected test
	output.

From-SVN: r223803

    PR libgomp/65742

    gcc/
    * builtins.c (expand_builtin_acc_on_device): Don't use open-coded
    sequence for !ACCEL_COMPILER.

    libgomp/
    * oacc-init.c (plugin/plugin-host.h): Include.
    (acc_on_device): Check whether we're in an offloaded region for
    host_nonshm
    plugin. Don't use __builtin_acc_on_device.
    * plugin/plugin-host.c (GOMP_OFFLOAD_openacc_parallel): Set
    nonshm_exec flag in thread-local data.
    (GOMP_OFFLOAD_openacc_create_thread_data): Allocate thread-local
    data for host_nonshm plugin.
    (GOMP_OFFLOAD_openacc_destroy_thread_data): Free thread-local data
    for host_nonshm plugin.
    * plugin/plugin-host.h: New.

From-SVN: r223801

2015-05-28  Robert Dewar  <dewar@adacore.com>

	* sem_ch13.adb, sem_disp.ads: Minor reformatting.

2015-05-28  Ed Schonberg  <schonberg@adacore.com>

	* sem_util.adb (Set_Debug_Info_Needed): For a private type
	whose full view is itself a derived private type, set flag on
	underlying full view as well, for proper gdb display.

2015-05-28  Bob Duff  <duff@adacore.com>

	* exp_tss.ads: Minor comment fix.
	* exp_ch3.adb (Build_Array_Init_Proc, Build_Record_Init_Proc):
	Inline init_procs when the type has controlled parts. Remove
	obsolete comments about those init_procs -- init_procs for
	such types are no longer complex. A typical init_proc just
	initializes the 'Tag field, and calls the parent init_proc
	(e.g. for Limited_Controlled), which calls the grandparent
	(for Root_Controlled), which does nothing. This all boils down
	to one instruction when inlined.
	* exp_ch7.adb (Create_Finalizer): Inline the finalizer.

2015-05-28  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch4.adb (Analyze_Selected_Component): If the type to use
	is a derived type and is a generic actual, the selected component
	appears within an instance body, and the check over the type
	has failed, examine ancestor types for the desired component.
	(Find_Component_In_Instance): If record type is a derived type,
	examine all ancestors in order to locate desired component.

From-SVN: r223800

	* config/rx/rx.c (push_regs): New function.  Extracts code from...
	(rx_expand_prologue): ... here.  Use push_regs to push even small
	spans of registers.
	(pop_regs): New function.
	(rx_expand_epilogue):  Use pop_regs to pop even small spans of
	registers.

From-SVN: r223799

2015-05-28  Richard Biener  <rguenther@suse.de>

	* tree-vectorizer.h (struct _slp_instance): Remove body_cost_vec
	member.
	(SLP_INSTANCE_BODY_COST_VEC): Remove.
	(vect_update_slp_costs_according_to_vf): Likewise.
	(vect_slp_analyze_operations): Update prototype.
	* tree-vect-loop.c (vect_analyze_loop_2): Remove call to
	vect_update_slp_costs_according_to_vf, adjust.
	* tree-vect-slp.c (vect_free_slp_instance): Adjust.
	(vect_analyze_slp_cost_1): Likewise.
	(vect_analyze_slp_cost): Likewise.  Properly deal with
	widening reduction ops.  Commit body costs.
	(vect_analyze_slp_instance): Adjust.  Do not analyze SLP
	cost for loops from here.
	(vect_slp_analyze_operations): But do it from here when
	the vectorization factor is known and stmts are analyzed.
	(vect_bb_vectorization_profitable_p): Simplify.
	(vect_slp_analyze_bb_1): Do not compute SLP cost here.
	(vect_update_slp_costs_according_to_vf): Remove.

From-SVN: r223798

Add --enable-default-pie option to configure GCC to generate PIE by
default.

gcc/

	* Makefile.in (COMPILER): Add @NO_PIE_CFLAGS@.
	(BUILD_CFLAGS): Likewise.
	(BUILD_CXXFLAGS): Likewise.
	(LINKER): Add @NO_PIE_FLAG@.
	(BUILD_LDFLAGS): Likewise.
	(libgcc.mvars): Set NO_PIE_CFLAGS to -fno-PIE for
	--enable-default-pie.
	* common.opt (fPIE): Initialize to -1.
	(fpie): Likewise.
	(no-pie): New option.
	(pie): Replace "Negative(shared)" with "Negative(no-pie)".
	* configure.ac: Add --enable-default-pie.
	(NO_PIE_CFLAGS): New.  Check if -fno-PIE works.  AC_SUBST.
	(NO_PIE_FLAG): New.  Check if -no-pie works.  AC_SUBST.
	* defaults.h (DEFAULT_FLAG_PIE): New.  Default PIE to -fPIE.
	* gcc.c (NO_PIE_SPEC): New.
	(PIE_SPEC): Likewise.
	(NO_FPIE1_SPEC): Likewise.
	(FPIE1_SPEC): Likewise.
	(NO_FPIE2_SPEC): Likewise.
	(FPIE2_SPEC): Likewise.
	(NO_FPIE2_SPEC): Likewise.
	(FPIE_SPEC): Likewise.
	(NO_FPIE_SPEC): Likewise.
	(NO_FPIC1_SPEC): Likewise.
	(FPIC1_SPEC): Likewise.
	(NO_FPIC2_SPEC): Likewise.
	(FPIC2_SPEC): Likewise.
	(NO_FPIC2_SPEC): Likewise.
	(FPIC_SPEC): Likewise.
	(NO_FPIC_SPEC): Likewise.
	(NO_FPIE1_AND_FPIC1_SPEC): Likewise.
	(FPIE1_OR_FPIC1_SPEC): Likewise.
	(NO_FPIE2_AND_FPIC2_SPEC): Likewise.
	(FPIE2_OR_FPIC2_SPEC): Likewise.
	(NO_FPIE_AND_FPIC_SPEC): Likewise.
	(FPIE_OR_FPIC_SPEC): Likewise.
	(LD_PIE_SPEC): Likewise.
	(LINK_PIE_SPEC): Handle -no-pie.  Use PIE_SPEC and LD_PIE_SPEC.
	* opts.c (finish_options): Update opts->x_flag_pie if it is -1.
	* config/darwin.h (PIE_SPEC): Renamed to ...
	(DARWIN_PIE_SPEC): This.
	(LINK_SPEC): Replace PIE_SPEC with DARWIN_PIE_SPEC.
	* config/darwin9.h (PIE_SPEC): Renamed to ...
	(DARWIN_PIE_SPEC): This.
	* config/gnu-user.h (GNU_USER_TARGET_STARTFILE_SPEC): Use
	PIE_SPEC and NO_PIE_SPEC if HAVE_LD_PIE is defined.
	* config/openbsd.h (ASM_SPEC): Use FPIE1_OR_FPIC1_SPEC and
	FPIE2_OR_FPIC2_SPEC.
	* config/m68k/netbsd-elf.h (ASM_SPEC): Likewise.
	* config/m68k/openbsd.h (ASM_SPEC): Likewise.
	* gcc/config/sol2.h (ASM_PIC_SPEC): Likewise.
	* config/arm/freebsd.h (SUBTARGET_EXTRA_ASM_SPEC): Likewise.
	* config/arm/netbsd-elf.h (SUBTARGET_EXTRA_ASM_SPEC): Likewise.
	* config/arm/semi.h (SUBTARGET_EXTRA_ASM_SPEC): Likewise.
	* config/cris/linux.h (CRIS_ASM_SUBTARGET_SPEC): Likewise.
	* config/m32r/m32r.h (ASM_SPEC): Likewise.
	* config/m68k/uclinux.h (DRIVER_SELF_SPECS): Likewise.
	* config/rs6000/linux64.h (ASM_SPEC32): Likewise.
	* config/rs6000/sysv4.h (ASM_SPEC): Likewise.
	* config/sparc/freebsd.h (ASM_SPEC): Likewise.
	* config/sparc/linux.h (ASM_SPEC): Likewise.
	* config/sparc/linux64.h (ASM_SPEC): Likewise.
	* config/sparc/netbsd-elf.h (ASM_SPEC): Likewise.
	* config/sparc/openbsd64.h (ASM_SPEC): Likewise.
	* config/sparc/sp-elf.h (ASM_SPEC): Likewise.
	* config/sparc/sp64-elf.h (ASM_SPEC): Likewise.
	* config/sparc/sparc.h (ASM_SPEC): Likewise.
	* config/sparc/sysv4.h (ASM_SPEC): Likewise.
	* config/sparc/vxworks.h (ASM_SPEC): Likewise.
	* config/c6x/elf-common.h (ASM_SPEC): Use NO_FPIC2_SPEC,
	FPIC2_SPEC, FPIC1_SPEC and FPIC2_SPEC.
	* config/c6x/uclinux-elf.h (LINK_SPEC): Use FPIE_SPEC.
	* config/frv/frv.h (DRIVER_SELF_SPECS): Use FPIC_SPEC,
	NO_FPIC_SPEC and NO_FPIE1_AND_FPIC1_SPEC.
	(ASM_SPEC): Use FPIE1_OR_FPIC1_SPEC and FPIE2_OR_FPIC2_SPEC.
	* config/m68k/m68k.h (ASM_PCREL_SPEC): Use FPIC_SPEC and
	NO_FPIC_SPEC.
	* config/mips/gnu-user.h (NO_SHARED_SPECS): Use
	NO_FPIE_AND_FPIC_SPEC.
	* config/mips/vxworks.h (SUBTARGET_ASM_SPEC): Use FPIC_SPEC.
	* config/rs6000/freebsd64.h (ASM_SPEC32): Likewise.
	* config/rs6000/vxworks.h (ASM_SPEC): Likewise.
	* config/vax/linux.h (ASM_SPEC): Likewise.
	* doc/install.texi: Document --enable-default-pie.
	* doc/invoke.texi: Document -no-pie.
	* config.in: Regenerated.
	* configure: Likewise.

gcc/ada/

	* gcc-interface/Makefile.in (TOOLS_LIBS): Add @NO_PIE_FLAG@.

libgcc/

	* Makefile.in (CRTSTUFF_CFLAGS): Add $(NO_PIE_CFLAGS).

From-SVN: r223796

From-SVN: r223795

	PR target/66148
	* config/pa/pa.c (pa_emit_move_sequence): Correct placement of
	REG_EQUAL note when doing insert.

From-SVN: r223791

	* config/pa/pa.c (pa_print_operand): Use HOST_WIDE_INT_PRINT_DEC
	instead of "%d" for 'o' operand.

From-SVN: r223790

From-SVN: r223788

        PR target/39726
        * gcc.dg/target/m68k/pr39726-1.c: New test.

From-SVN: r223781

2015-05-27  Uros Bizjak  <ubizjak@gmail.com>

	* config/linux/wait.h (gomp_futex_wait, gomp_futex_wake):
	Declare as int.
	(FUTEX_PRIVATE_FLAG): Remove L suffix.
	* config/linux/mutex.c (gomp_futex_wait, gomp_futex_wake):
	Declare as int.

2015-05-27  Uros Bizjak  <ubizjak@gmail.com>

	* config/linux/ia64/futex.h (sys_futex0) Change operand "op" to int.

2015-05-27  Uros Bizjak  <ubizjak@gmail.com>

	Revert:
	* config/linux/x86/futex.h (sys_futex0) [!__x86_64__]:
	Change operand "op" to long.

From-SVN: r223780

decl.c (check_redeclaration_exception_specification): Depend on -Wsystem-headers rather than -pedantic.

	* decl.c (check_redeclaration_exception_specification): Depend on
	-Wsystem-headers rather than -pedantic.

From-SVN: r223778

decl.c (warn_extern_redeclared_static): Use the location of newdecl in diagnostics, not input_location.

	* decl.c (warn_extern_redeclared_static): Use the location of
	newdecl in diagnostics, not input_location.
	(validate_constexpr_redeclaration): Likewise.
	(check_redeclaration_no_default_args): Likewise.
	(duplicate_decls): Likewise.
	(check_redeclaration_exception_specification): Likewise.
	Change second diagnostic to inform.

From-SVN: r223777

From-SVN: r223775

From-SVN: r223774

	PR c++/66270
	* tree.c (build_pointer_type_for_mode): Canonical type does not
	inherit can_alias_all.
	(build_reference_type_for_mode): Likewise.

	PR c++/66270
	* g++.dg/ext/alias-canon3.C: New.

From-SVN: r223773

trans.c (elaborate_all_entities): Do not elaborate an incomplete type coming from a limited_with and whose...

	* gcc-interface/trans.c (elaborate_all_entities): Do not elaborate an
	incomplete type coming from a limited_with and whose non-limited view
	comes from the main unit.

From-SVN: r223772

libgomp/ChangeLog:

	* config/linux/x86/futex.h (sys_futex0) [!__x86_64__]:
	Change operand "op" to long.
	[__PIC__]: Remove sys_futex0 function.

libitm/ChangeLog:

	* config/linux/x86/futex_bits.h (sys_futex0) [!__x86_64__]:
	Change operand "op" to long.
	[__PIC__]: Remove sys_futex0 function.

From-SVN: r223771

	* expr.h (array_at_struct_end_p): Move to...
	(array_ref_element_size): Likewise.
	(component_ref_field_offset): Likewise.
	* tree.h (array_ref_element_size): ...here.
	(array_at_struct_end_p): Likewise.
	(component_ref_field_offset): Likewise.
	* expr.c (array_ref_element_size): Move to...
	(array_ref_low_bound): Likewise.
	(array_at_struct_end_p): Likewise.
	(array_ref_up_bound): Likewise.
	(component_ref_field_offset): Likewise.
	* tree.c (array_ref_element_size): ...here.
	(array_ref_low_bound): Likewise.
	(array_ref_up_bound): Likewise.
	(array_at_struct_end_p): Likewise.
	(component_ref_field_offset): Likewise.

From-SVN: r223768

	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Variable>: Move down
	code applying atomic checks to the object.

From-SVN: r223767

gcc/Changelog:

2015-05-27  Gregor Richards  <gregor.richards@uwaterloo.ca>
	    Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* config/aarch64/aarch64-linux.h (MUSL_DYNAMIC_LINKER): Define.


Co-Authored-By: Szabolcs Nagy <szabolcs.nagy@arm.com>

From-SVN: r223766

        * config.host (i[34567]86-*-freebsd*, x86_64-*-freebsd*): Set
        md_unwind_header
        * config/i386/freebsd-unwind.h: New.

From-SVN: r223765

	PR bootstrap/66304
config/
	* warnings.m4 (ACX_PROG_CXX_WARNING_OPTS)
	(ACX_PROG_CXX_WARNINGS_ARE_ERRORS)
	(ACX_PROG_CXX_WARNING_ALMOST_PEDANTIC): New.
	(ACX_PROG_CC_WARNING_OPTS, ACX_PROG_CC_WARNING_ALMOST_PEDANTIC)
	(ACX_PROG_CC_WARNINGS_ARE_ERRORS): Push into C language context.
gcc/
	* configure.ac: Use ACX_PROG_CXX_WARNING_OPTS,
	ACX_PROG_CXX_WARNING_ALMOST_PEDANTIC, and
	ACX_PROG_CXX_WARNINGS_ARE_ERRORS.
	* configure: Regenerate.

From-SVN: r223763

	* auto-profile.c (afdo_calculate_branch_prob): Break once has_sample is
	true.

From-SVN: r223762

From-SVN: r223761

2015-05-27  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66272
	Revert parts of
	2014-08-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/62031
	* tree-data-ref.c (dr_analyze_indices): Do not set
	DR_UNCONSTRAINED_BASE.
	(dr_may_alias_p): All indirect accesses have to go the
	formerly DR_UNCONSTRAINED_BASE path.
	* tree-data-ref.h (struct indices): Remove
	unconstrained_base member.
	(DR_UNCONSTRAINED_BASE): Remove.

	* gcc.dg/torture/pr66272.c: New testcase.

From-SVN: r223759

	* dwarf2out.c: Remove block_map.
	(gen_call_site_die): Replace block_map use with BLOCK_DIE.
	(gen_lexical_block_die): Same.
	(dwarf2out_function_decl): Remove block_map use.
	(dwarf2out_c_finalize): Same.
	* tree-core.h (struct tree_block): Add die field.
	* tree.h (BLOCK_DIE): New.

From-SVN: r223758

2015-05-27  Richard Biener  <rguenther@suse.de>

	* gcc.dg/vect/slp-reduc-7.c: New testcase.

From-SVN: r223756

2015-05-27  Robert Dewar  <dewar@adacore.com>

	* sem_aux.adb: Minor rewording.

2015-05-27  Bob Duff  <duff@adacore.com>

	* exp_prag.adb (Expand_Pragma_Abort_Defer): Make
	pragma Abort_Defer do nothing if Abort_Allowed is False.

2015-05-27  Arnaud Charlet  <charlet@adacore.com>

	* exp_ch9.adb, sem_util.adb, sem_util.ads, s-stposu.adb, s-spsufi.ads,
	sem_elab.ads, g-comlin.ads, errout.ads, exp_ch6.adb, sem_ch4.adb,
	opt.ads, s-bignum.adb, output.ads, sem_ch13.adb, erroutc.ads,
	sem_disp.ads, exp_ch3.adb: Minor fixes of duplicate words in comments.

2015-05-27  Doug Rupp  <rupp@adacore.com>

	* adaint.c (__gnat_tmp_name) [vxworks]: Robustify and use for rtp as
	well as kernel.

2015-05-27  Pierre-Marie de Rodat  <derodat@adacore.com>

	* par_sco.adb (Process_Decision): Store sloc to
	condition/pragmas SCOs associations into a temporary table before
	moving them to the SCO_Raw_Hash_Table so that we can back them
	out just like we do for SCO entries that are simple decisions
	in an expression context.

From-SVN: r223754

	PR target/65358
	* expr.c (memory_load_overlap): New function.
	(emit_push_insn): When pushing partial args to the stack would
	clobber the register part load the overlapping part into a pseudo
	and put it into the hard reg after pushing.  Change return type
	to bool.  Add bool argument.
	* expr.h (emit_push_insn): Change return type to bool.
	Add bool argument.
	* calls.c (expand_call): Cancel sibcall optimization when encountering
	partial argument on targets with ARGS_GROW_DOWNWARD and
	!STACK_GROWS_DOWNWARD.
	(emit_library_call_value_1): Update callsite of emit_push_insn.
	(store_one_arg): Likewise. 

	PR target/65358
	* gcc.dg/pr65358.c: New test.

From-SVN: r223753

2015-05-27  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch6.adb (Process_Formals): A non-private formal type that
	is a limited view does not have a list of private dependents.

2015-05-27  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch5.adb (Expand_N_Case_Statement): If the expression in
	the case statement is a compile-time known value, we look for a
	corresponding alternative to optimize the case statement into a
	single case. If the type has a static predicate and the expression
	does not satisfy the predicate, there is no legal alternative and
	this optimization is not applicable.  Excecution is erroneous,
	or else if assertions are enabled, an exception will be raised
	earlier, at the point the expression is elaborated.

2015-05-27  Robert Dewar  <dewar@adacore.com>

	* sem_elab.adb (Check_Internal_Call_Continue): Suppress
	warning on Finalize, Adjust, or Initialize if type involved has
	Warnings_Off set.

2015-05-27  Ed Schonberg  <schonberg@adacore.com>

	* sem_aux.adb, sem_aux.ads (First_Discriminant): Return empty when
	applied to a type with no known discriminants.

From-SVN: r223752