Adds a second build of host packages.

Adds a second build of host packages and do some testing, which
mimics the ways chromiumos-sdk cbuildbot does.

So actually we perform 2 builds of all host packages -
  1. build new toolchain using old toolchain and build all host packages
     using the newly built toolchain
  2. build the new toolchain again but using new toolchain built in step 1,
     and build all host packages using the newly built toolchain

TEST=locally
BUG=None

Change-Id: Ic35092893b10860ca1112a1abb3356a279d36869
Reviewed-on: https://chrome-internal-review.googlesource.com/163325
Reviewed-by: Luis Lozano <llozano@chromium.org>
Commit-Queue: Han Shen <shenhan@google.com>
Tested-by: Han Shen <shenhan@google.com>
1 file changed