* flag-types.h (enum sanitize_code): Add SANITIZE_BUILTIN.  Or
	SANITIZE_BUILTIN into SANITIZE_UNDEFINED.
	* sanitizer.def (BUILT_IN_UBSAN_HANDLE_INVALID_BUILTIN,
	BUILT_IN_UBSAN_HANDLE_INVALID_BUILTIN_ABORT): New builtins.
	* opts.c (sanitizer_opts): Add builtin.
	* ubsan.c (instrument_builtin): New function.
	(pass_ubsan::execute): Call it.
	(pass_ubsan::gate): Enable even for SANITIZE_BUILTIN.
	* doc/invoke.texi: Document -fsanitize=builtin.

	* c-c++-common/ubsan/builtin-1.c: New test.

From-SVN: r253888