The wasm memory deserialization didn't properly increment the object id, so
wouldn't work properly if the memory object (or its contained
SharedArrayBuffer) where included multiple times in the object.

Bug: v8:6895
Change-Id: I5c4c25bad2ec6152883c5a7321038aba1950480a
Reviewed-on: https://chromium-review.googlesource.com/721630Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Ben Smith <binji@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48767}