The heap broker expects that handles get canonicalized.

R=jarin@chromium.org

Bug: v8:7790
Change-Id: If6162316bb2a256e783a8175ac7d4172d040b28b
Reviewed-on: https://chromium-review.googlesource.com/1155123
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54823}