The flag is useful for disabling tests that are not supported in
the third_party_heap build configuration.

Example usage in the status files:
['third_party_heap', {
  'testname': [SKIP],
}],  # third_party_heap

Bug: v8:11155
Change-Id: I991532bf7cdf89d8c505e4d6cbd7cf9e4d70dd63
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2821960
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73957}