re PR lto/61886 (LTO breaks fread with _FORTIFY_SOURCE=2)

re PR lto/61886 (LTO breaks fread with _FORTIFY_SOURCE=2)

	PR ipa/61886
	PR middle-end/25140
	* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Use compare_base_decls
	(nonoverlapping_component_refs_of_decl_p): Update sanity check.
	(decl_refs_may_alias_p): Use compare_base_decls.
	* alias.c: Include cgraph.h
	(rtx_equal_for_memref_p): Use rtx_equal_for_memref_p.
	(compare_base_decls): New function.
	(base_alias_check): Likewise.
	(memrefs_conflict_p): Likewise.
	(nonoverlapping_memrefs_p): Likewise.
	* alias.h (compare_base_decls): Declare.

	* gcc.c-torture/execute/alias-2.c: New testcase.

From-SVN: r231478