expr.c (get_inner_reference): Sign-extend the constant twos-complement offset before doing arbitrary...

2011-08-18  Richard Guenther  <rguenther@suse.de>

	* expr.c (get_inner_reference): Sign-extend the constant
	twos-complement offset before doing arbitrary precision
	arithmetic on it.
	* tree-ssa-structalias.c (get_constraint_for_ptr_offset): Likewise.
	(get_constraint_for_1): Pass the offset of a MEM_REF unchanged
	to get_constraint_for_ptr_offset.

From-SVN: r177847