These excludes are used in images and I want to use the same checking
code as images do so the build root needs to behave the same way.
This is temporary as I'll switch to installing libc via emerge soon.
The cross toolchain doesn't have lib symlinks but this works because it
also doesn't install things to lib. However when this script manually
extracts the toolchain packages to BOARD_ROOT tar includes those empty
directories, replacing the symlinks that were previously there.
Longer term this really needs to go away, whatever build time is saved
by re-using the cross toolchain packages in BOARD_ROOT is not worth this
insane level of complexity it causes...
Move cross toolchain library install code out of setup_board to a
separate script, and have setup_board use it.
The install_toolchain script will be used by the builders to set up
a separate sysroot (distinct from the /build/<board> root), as part of
the Simplified Chrome Workflow (goto/simple-chrome).
BUG=chromium-os:36299
TEST=locally, trybots.
Change-Id: I88c355f1798da71ead9370a82365304dbf311504
Reviewed-on: https://gerrit.chromium.org/gerrit/38156
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Ryan Cui <rcui@chromium.org>
Tested-by: Ryan Cui <rcui@chromium.org>
