This fixes a bug caused by StartFunction() being called for an invalid
module.

Bug: v8:7748
Change-Id: I47a3f3573355d87554b123dd1edc7c829bb43d0e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2423710
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70081}