Recently, a gcc-4.4.6 has been unmasked in the host, but no effort
has been made to make sure the developers select it with gcc-config.
BUG=chromium-os:19613
TEST=ran the tests below with set -x and observed
1) manually set the MINIMUM version to 4.4.7, see it fail
2) two gccs, current + old, set to old, observed the switch and unmerge
3) above, but set to new, same result
4) only one gcc, the current, observed nothing happening
5) only have old gcc, let the script update&select new one, unmerge old
Change-Id: Id2a285a13f5b27d7531eae4db35e36f6b8cc5f4f
Reviewed-on: http://gerrit.chromium.org/gerrit/6694
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: Zdenek Behan <zbehan@chromium.org>
