Since embedded builtins will be disabled by default until after the
M67 branch point, let's enable them on two specific bots to at least
have some continued coverage.

release_x64_internal is a release build (with an internal snapshot).
release_x64_verify_csa is a pseudo-debug build with DEBUG set.

Bug: v8:6666
Change-Id: I7e81c24e3cefc6eeba5d6e5823d47ab52f3e5941
Reviewed-on: https://chromium-review.googlesource.com/983597Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52274}