If return's input counts did not change, there is no need to change the
node at all.

Bug: chromium:1127620
Change-Id: I16d14a273d44b9fcd0b5a8af74b7a5a2eda569ff
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2434998
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70183}