re PR lto/56168 (GCC seems to disregard -fno-builtin when compiling with LTO)

2013-02-04  Richard Guenther  <rguenther@suse.de>

	PR lto/56168
	* lto-symtab.c (lto_symtab_merge_decls_1): Make non-builtin
	node prevail as last resort.
	(lto_symtab_merge_decls): Remove guard on LTRANS here.
	(lto_symtab_prevailing_decl): Builtins are their own prevailing
	decl.

	lto/
	* lto.c (read_cgraph_and_symbols): Do not call lto_symtab_merge_decls
	or lto_fixup_decls at LTRANS time.

	* gcc.dg/lto/pr56168_0.c: New testcase.
	* gcc.dg/lto/pr56168_1.c: Likewise.

From-SVN: r195709