This patch includes a test for this issue.
The V8 patch is intentionally left simple to avoid merge conflicts in
the future. To be landed upstream, the `unwindinfo_use_count_` would
probably have to be made non-atomic and we'd have to add a cctest.
Upstream bug: https://bugs.chromium.org/p/v8/issues/detail?id=12393
Fixes: #714
