This is no longer needed now that Wasm is more aggressive about
collecting old memories. It also causes problems with the upcoming trap
handler fallback path.

Change-Id: I4b8513c28e0c0d7c6b232d399c1d97b645499ef1
Reviewed-on: https://chromium-review.googlesource.com/1043277Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Eric Holk <eholk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53425}