buildgcc: Relax GNAT version checks

Compiling the GNAT frontend of GCC seems to have stabilized since GCC
4.9.0. So build it by default if GNAT >= 4.9 is installed.

TEST=Bootstrapped all GCC versions from 4.9.0 to 6.2 and built the
     i386 cross toolchain with each.

Change-Id: I9d1127595dc6b9bcece9c5e5cc7e45f467744ab9
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/18777
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

0 files changed, 0 insertions, 0 deletions