This experimentally implements taring/untaring the test data
for test262 on the v8-side before test isolation and when
running the tests.

It archives on demand only if the tar is outdated compared
to the contained files. This comes with a cost of ~1s extra
to run gyp on linux and ~6s extra on windows. Ninja is
lightning fast afterwards in detecting changes. Also, we
archive only when test_isolation_mode is set and when
the test262_run target is required.

The archiving itself costs ~30s on all platforms. But as the
files will change seldom this shouldn't have a big impact.

Extraction on the test runner side is below 2s on mac and
linux. The speedup is enormous. Around 5 minutes were spent
on download on swarming slaves before, which is now only
a few seconds. So total test time for release (no variants),
e.g. goes from 8 to 3 minutes.

BUG=chromium:535160
LOG=n

Review URL: https://codereview.chromium.org/1713993002

Cr-Commit-Position: refs/heads/master@{#34155}