re PR middle-end/47893 (4.6 miscompiles mesa on i686)

re PR middle-end/47893 (4.6 miscompiles mesa on i686)

	PR middle-end/47893
	* rtl.h (ASLK_REDUCE_ALIGN, ASLK_RECORD_PAD): Define.
	(assign_stack_local_1): Change last argument type to int.
	* function.c (assign_stack_local_1): Replace reduce_alignment_ok
	argument with kind.  If bit ASLK_RECORD_PAD is not set in it,
	don't record padding space into frame_space_list nor
	use those areas.
	(assign_stack_local): Adjust caller.
	(assign_stack_temp_for_type): Call assign_stack_local_1 instead
	of assign_stack_local, pass 0 as last argument.
	* caller-save.c (setup_save_areas): Adjust assign_stack_local_1
	callers.

	* gcc.dg/pr47893.c: New test.

From-SVN: r170568