This has been functionally obsolete for a while now. From a performance
point of view it also became obsolete, because the only on-heap {Code}
object being generated within this scope is the start function wrapper.

R=clemensh@chromium.org
BUG=v8:6792

Change-Id: I978488fbd8d26b55d957d56449c5ff021b888ce1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1532320Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60374}