crossgcc: disable libsanitizer for the bootstrapped compiler

Ironically enough, libsanitizer is notorious for creating "uninitialized
variable" warnings with different compiler versions than the one it's
shipping with.

Since we don't need it for building the real compiler, just skip it.

Fixes building our compilers using the gnat-gpl 2014 compilers.

Change-Id: I2130dfdf3eaf07d77cd70777419fc0ae4642b843
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/19478
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>

util/crossgcc/buildgcc

@@ -600,6 +600,7 @@ bootstrap_GCC() {
 		--disable-werror --disable-nls \
 		--disable-shared --disable-multilib \
 		--disable-libssp --disable-libquadmath --disable-libcc1 \
+		--disable-libsanitizer \
 		${GCC_OPTIONS} --enable-languages="${LANGUAGES}" \
 		--with-gmp=$DESTDIR$TARGETDIR --with-mpfr=$DESTDIR$TARGETDIR \
 		--with-mpc=$DESTDIR$TARGETDIR --with-libelf=$DESTDIR$TARGETDIR \