This adds the ability for the test runner to parse unexpected crashes
from the stdout. It also processes the stdout to determine which tests
failed. Tests that run after the crash are re-tried in a follow-up
child process.

Will allow for the test runner to handle very crashy test suites and
also processes crashes from win-asan and other configs where it is
harder to intercept crashes.

Bug: angleproject:5251
Change-Id: Iee03130622571580cb7910f4fb097fe3659d75ec
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2513288
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>