For serialization we are using the code table to find the code of all
functions. We want to serialize compiled code though, not interpreter
entries (we currently fail a DCHECK there).
This CL changes the logic to not update the code table with interpreter
entries but instead keeps a separate bit set of interpreted functions.

R=mstarzinger@chromium.org

Bug: v8:8177, chromium:735509
Change-Id: I69c59f92712135ddef667b54114614fad94cc6fc
Reviewed-on: https://chromium-review.googlesource.com/c/1278794Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56644}