* configure.ac: Sync with GCC repo.
	* configure: Ditto.
	* Makefile.def: Ditto.
	* Makefile.in: Ditto.
	* configure: Regenerate after syncing config/.
	PR go/55969
	* configure.ac: Disable libgo on some systems where it does not
	work.
	* configure: Rebuild.
	* configure.ac: Sync with GCC repo.
	* configure: Ditto.