* gcc-interface/ada-tree.h (DECL_LOOP_PARM_P): New flag.
	(DECL_INDUCTION_VAR): New macro.
	(SET_DECL_INDUCTION_VAR): Likewise.
	* gcc-interface/gigi.h (convert_to_index_type): Declare.
	(gnat_invariant_expr): Likewise.
	* gcc-interface/decl.c (gnat_to_gnu_entity) <object>: If this is a loop
	parameter, set DECL_LOOP_PARM_P on it.
	* gcc-interface/misc.c (gnat_print_decl) <VAR_DECL>: If DECL_LOOP_PARM_P
	is set, print DECL_INDUCTION_VAR instead of DECL_RENAMED_OBJECT.
	* gcc-interface/trans.c (gnu_loop_label_stack): Delete.
	(struct range_check_info_d): New type.
	(struct loop_info_d): Likewise.
	(gnu_loop_stack): New stack.
	(Identifier_to_gnu): Set TREE_READONLY flag on the first dereference
	built for a by-double-ref read-only parameter.  If DECL_LOOP_PARM_P
	is set, do not test DECL_RENAMED_OBJECT.
	(push_range_check_info): New function.
	(Loop_Statement_to_gnu): Push a new struct loop_info_d instead of just
	the label.  Reference the label and the iteration variable from it.
	Build the special induction variable in the unsigned version of the
	size type, if it is larger than the base type.  And attach it to the
	iteration variable if the latter isn't by-ref.  In the iteration scheme
	case, initialize the invariant conditions in front of the loop if
	deemed profitable.  Use gnu_loop_stack.
	(gnat_to_gnu) <N_Exit_Statement>: Use gnu_loop_stack.
	<N_Raise_Constraint_Error>: Always process the reason.  In the range
	check and related cases, and if loop unswitching is enabled, compute
	invariant conditions and push this information onto the stack.
	Do not translate again the condition if it has been already translated.
	* gcc-interface/utils.c (record_global_renaming_pointer): Assert that
	DECL_LOOP_PARM_P isn't set.
	(convert_to_index_type): New function.
	* gcc-interface/utils2.c (build_binary_op) <ARRAY_REF>: Use it in order
	to convert the index from the base index type to sizetype.
	(gnat_invariant_expr): New function.

From-SVN: r179868