* builtins.c (is_valid_printf_arglist, expand_builtin_printf):
	Move functions from here ...

	* c-common.c (is_valid_printf_arglist, c_expand_builtin_printf):
	... to here.
	(c_expand_builtin): New function.
	(init_function_format_info): Don't set `check_function_format_ptr'.
	(c_common_nodes_and_builtins): Set built_in_class type for
	printf/__builtin_printf to BUILT_IN_FRONTEND.
	(c_expand_expr): Handle CALL_EXPRs that are front-end builtins.

	* c-common.h (build_function_call): Declare.

	* expr.c (expand_expr): Pass builtins with class BUILT_IN_FRONTEND
	to `lang_expand_expr' rather than `expand_builtin'.

	* tree.c (check_function_format_ptr): Delete.

	* tree.h (check_function_format_ptr): Likewise.

From-SVN: r36758