* builtins.c (fold_builtin_strstr): Removed.
	(fold_builtin_2): Don't call fold_builtin_strstr.
	* gimple-fold.c (gimple_fold_builtin_strchr): Check is_strrchr
	earlier in the strrchr (x, 0) -> strchr (x, 0) optimization.
	(gimple_fold_builtin_strstr): New function.
	(gimple_fold_builtin): Call it.
	* fold-const-call.c (fold_const_call): Handle CFN_BUILT_IN_STRSTR.

	* gcc.dg/builtin-strstr-1.c: New test.
	* g++.dg/cpp0x/constexpr-strstr.C: New test.

From-SVN: r243378