PR tree-optimization/14819

	* builtins.c (fold_builtin_strchr): New.
	(fold_builtin_1): Handle BUILT_IN_STRCHR and BUILT_IN_STRRCHR
	with fold_builtin_strchr().


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@82464 138bc75d-0d04-0410-961f-82ee72b054a4