pypy3-exe: Add patch to not override CC

pypy3's build probes for `gcc` and overrides the CC variable if found in
some cases. We don't ever want that in our build, so change its behavior
to only set CC if it is otherwise unset.

BUG=chromium:1114277
TEST=`emerge pypy3-exe`

Change-Id: I21bab95fe31416251694e05ff615108d137f30b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2399423
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
2 files changed