TryLookupCode can be passed arbitrary addresses, e.g. by tentative
name lookups during disassembly. This CL makes sure that addresses
within non-builtin-code sections of the embedded blob (metadata or
padding) are handled properly.

Bug: v8:6666, v8:8334
Change-Id: I42eca57062e30eabd7bb1b069786aa809706cd2c
Reviewed-on: https://chromium-review.googlesource.com/c/1292060Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56865}