PR optimization/6631
	* Makefile.in (function.o): Depend on langhooks.h.
	* alias.c (objects_must_conflict_p): Check honor_readonly when
	examining TYPE_READONLY.
	* function.c (assign_stack_temp_for_type): Likewise.

	PR optimization/6631
	* g++.dg/opt/const2.C: New test.

From-SVN: r58136