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
	* ipa-reference.c (is_improper): Break out from ...
	(is_proper_for_analysis): ... here; fix WRT aliases.
	(analyze_function, generate_summary,
	ipa_reference_write_optimization_summary,
	ipa_reference_read_optimization_summary): Use ipa_reference_var_uid.
	* ipa-refrence.h (ipa_reference_var_uid): New inline.
	* tree-ssa-alias.c (ref_maybe_used_by_call_p_1,
	call_may_clobber_ref_p_1): Use ipa_reference_var_uid.

	* gcc.c-torture/execute/alias-3.c: New testcase.

From-SVN: r231442