Prior to this CL, TraverseTransitionTree was a recursive post-order
visitor. This led to stack overflows for deep transition trees.

This CL changes to an iterative DFS algorithm instead. Since no user
seems to rely on the visitation order, it was changed from postorder to
preorder for ease of implementation.

Bug: chromium:1224935
Change-Id: Ibda199422fb20fb4470c5c68947e0afbd9a5e596
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3084366
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76195}