The condition can change between VisitBranch and VisitIf, so VisitIf
can't assume that the condition is not yet in the ControlPathConditions
list. Thanks Manos!

Change-Id: Ic74253b6faf2663cfa5212765d81392cb89d73b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2773312Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73539}