* c-common.c (c_common_lang_init): New function.  Warn if format
	warning options which only have effects when used with -Wformat
	are used without -Wformat.
	* c-common.h (c_common_lang_init): Declare.
	* c-lang.c (lang_init): Call c_common_lang_init.
	* objc/objc-act.c (lang_init): Call c_common_lang_init.

cp:
	* lex.c (lang_init): Call c_common_lang_init.

From-SVN: r38672