This will give us much better testing coverage for trap-based bounds
checks.

Note that this will not enable the trap handler by default in Chrome.
Instead, Chrome will need to explicitly enable the feature using
V8::EnableWebAssemblyTrapHandler.

Bug: v8:5277
Change-Id: I7d81f40c6f831c6fe7926375c677908952b78fa2
Reviewed-on: https://chromium-review.googlesource.com/964711Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Eric Holk <eholk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52627}