2017-07-07  Torsten Duwe  <duwe@suse.de>

        c-family/
	* c-attribs.c (c_common_attribute_table): Add entry for
	"patchable_function_entry".

        lto/
	* lto-lang.c (lto_attribute_table): Add entry for
	"patchable_function_entry".

	* common.opt: Introduce -fpatchable-function-entry
	command line option, and its variables function_entry_patch_area_size
	and function_entry_patch_area_start.
	* opts.c (common_handle_option): Add -fpatchable_function_entry_ case,
	including a two-value parser.
	* target.def (print_patchable_function_entry): New target hook.
	* targhooks.h (default_print_patchable_function_entry): New function.
	* targhooks.c (default_print_patchable_function_entry): Likewise.
	* toplev.c (process_options): Switch off IPA-RA if
	patchable function entries are being generated.
	* varasm.c (assemble_start_function): Look at the
	patchable-function-entry command line switch and current
	function attributes and maybe generate NOP instructions by
	calling the print_patchable_function_entry hook.
	* doc/extend.texi: Document patchable_function_entry attribute.
	* doc/invoke.texi: Document -fpatchable_function_entry
	command line option.
	* doc/tm.texi.in (TARGET_ASM_PRINT_PATCHABLE_FUNCTION_ENTRY):
	New target hook.
	* doc/tm.texi: Re-generate.

	* c-c++-common/patchable_function_entry-default.c: New test.
	* c-c++-common/patchable_function_entry-decl.c: Likewise.
	* c-c++-common/patchable_function_entry-definition.c: Likewise.

From-SVN: r250521