hooks: forces llvm-libunwind and gcc-libs to be emerged for boards

Since the libunwind roll, chroots that have recently updated are in
limbo between libgcc_eh and libunwind. This new hook will force all
chroots to update their boards to using libunwind as the unwind library.

BUG=b:210927982
TEST=./update_chroot installed llvm-libunwind

Change-Id: Ic352e0d4482fd1fba133d6640cfc2cc493af8116
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3343927
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Sergey Frolov <sfrolov@google.com>
Tested-by: Christopher Di Bella <cjdb@google.com>
Auto-Submit: Christopher Di Bella <cjdb@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed