* c-decl.c (grokdeclarator): Diagnose _Noreturn for non-C1X if
	pedantic.
	* c-parser.c (c_parser_declspecs): Include _Noreturn in syntax
	comment.
	* ginclude/stdnoreturn.h (noreturn): Don't define for C++.

testsuite:
	* gcc.dg/c90-noreturn-1.c, gcc.dg/c99-noreturn-1.c: New tests.

From-SVN: r177899