re PR tree-optimization/19967 (built-in folding causes excess diagnostics)

re PR tree-optimization/19967 (built-in folding causes excess diagnostics)

	PR tree-optimization/19967
	* builtins.c (expand_builtin_strstr, expand_builtin_strpbrk,
	expand_builtin_strchr, expand_builtin_strrchr): Take a new
	argument TYPE.  Adjust calls to fold_builtin_XXX.
	(expand_builtin, fold_builtin_1): Adjust calls to
	expand_builtin_XXX.
	(fold_builtin_strchr, fold_builtin_strpbrk,
	fold_builtin_strstr, fold_builtin_strrchr): Convert the folded
	result to a requested type TYPE.

	* testsuite/gcc.dg/pr19967.c: New.

From-SVN: r95109