cbfstool: guard _Static_assert

This isn't required for correct execution, and doesn't need to be tested
on every single compiler out there.

Since GCC < 4.5 has no idea about _Static_assert, hide it there. Our
build tests will make sure that the test is run before changes are
submitted to master.

Change-Id: I4141f4aa23b140d2d1017ca7b4dace5aa7db0c04
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/11475
Tested-by: build bot (Jenkins)
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
1 file changed