cros_setup_toolchains: take direct control of host packages

We've been relying on crossdev to provide a list of packages for the
host toolchain, and then either undoing the results (like gdb) or
inserting more results by hand (like llvm) or munging the categories
(and thus partially ignoring the crossdev results).  Since we don't
need or want crossdev to manage config files for the host sdk like
we do with target packages (e.g. /etc/portage/*/cross-$CHOST and
/usr/local/portage/crossdev/cross-$CHOST/ paths), we end up gaining
very little from this.

Instead, lets manage the list of host toolchain packages directly.
This makes the code clearer and easier to add more packages (which
we seem to be doing more of).

BUG=chromium:751852, b:162254118
TEST=precqs pass
TEST=`cros tryjob chromiumos-sdk` passes
TEST=`cros tryjob --latest-toolchain lumpy-release` passes

Change-Id: Ic61cd26cc763a600134b80da73e7144251abadc3
Reviewed-on: https://chromium-review.googlesource.com/664099
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2478983
Tested-by: Patryk Duda <patrykd@google.com>
Commit-Queue: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
1 file changed