If a loop is removed in dead code elimination, we may have a dead node
in the control chain. This wasn't expected, and endless recursion could
result.

Bug: chromium:1196185
Change-Id: Id6d69d0eaed11b0c6158b5643d3433b11611af59
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2817792Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73906}