[plan] Update gcc-libs plan to copy libs from chef/gcc package.
[plan] Update gcc-libs plan to copy libs from chef/gcc package.

This seems like a worthwhile shortcut as it prevents us from having to
completely compile gcc twice over. This plan build time goes from about 10
minutes (on fast hardware) to 2 seconds. Not bad.

be-plans/be,be-plans/be,be-plans/be,be-plans/be