[CPP PATCH] Fix warning & other cleanups.

[CPP PATCH] Fix warning & other cleanups.

https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01162.html
	* directives.c (do_undef): Use cpp_macro_p & cpp_builtin_macro_p.
	* include/cpplib.h (enum cpp_macro_kind): Remove trailing comma.
	(cpp_fun_like_macro_p): Make inline, define.
	* macro.c (cpp_define_lazily): Use UCHAR_MAX.
	(cpp_fun_like_macro_p): Delete.

From-SVN: r263666