fold-const.c (fold): Fold difference of addresses.

	* fold-const.c (fold): Fold difference of addresses.
	(ptr_difference_const): Moved from tree-ssa-loop-ivopts, based on
	get_inner_reference.
	* tree-ssa-loop-ivopts.c (peel_address): Removed.
	(ptr_difference_const): Moved to fold-const.c.
	(split_address_cost): Use get_inner_reference instead of peel_address.
	(ptr_difference_cost): Change type of diff to HOST_WIDE_INT.
	* tree.h (ptr_difference_const): Export.

	* tree-ssa-loop-ivopts.c (dump_iv, dump_use, dump_cand): Add induction
	variable type to the dump.  Fix indentation.
	(idx_find_step): Handle nonconstant array_ref_element_size and
	array_ref_low_bound.
	(idx_record_use): Handle array_ref_element_size and
	array_ref_low_bound.
	(find_interesting_uses_stmt): Handle memory = nontrivial_expression
	statements correctly.
	(get_computation_at, iv_value): Do not unshare expressions here.
	(rewrite_use_outer): Unshare the expression before it is emitted
	to code.
	* tree-ssa-loop-niter.c (unsigned_type_for, signed_type_for):
	Moved to tree.c.
	* tree.c (unsigned_type_for, signed_type_for): Moved from
	tree-ssa-loop-niter.c.  Use langhooks.
	* tree.h (signed_type_for): Export.

From-SVN: r87601