* Makefile.in (bversion.h, s-bversion): New targets.
	(TOPLEV_H): Add bversion.h.
	* toplev.h: Include "bversion.h".
	(ATTRIBUTE_GCC_DIAG): When building with checking disabled, use
	the __format__ attribute only if compiling with the same version
	of GCC as the sources (the "build version").

From-SVN: r147792