This moves the verify-predictable logic from the test runner into
a python wrapper script.

This revealed two more tests that don't print allocations, which are
now skipped.

Bug: v8:7166, v8:7177
Change-Id: Ie4a541cb2a20900414ffe1caf4b3fccc4a5edb52
Reviewed-on: https://chromium-review.googlesource.com/808971
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49964}