This extends the validity checking of relocation information from only
non-anonymous {WasmCode} objects to all (even anonymous) such objects,
including code being copied in from the garbage-collected heap.

R=jgruber@chromium.org

Change-Id: Icbc842ad819f4471cc11d3d19bbde1d192731569
Reviewed-on: https://chromium-review.googlesource.com/1073284Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53383}