This CL introduces an additional verification pass at the end of
SimplifiedLowering. The verification checks consistency of the lowered
graph with respect to node types under the effect of used truncations.
Typing of additional, lower level nodes is required and added in this
CL.

The verification pass can be enabled using --verify-simplified-lowering.

Bug: v8:12619, v8:11682
Change-Id: I21e7ebcf40153e53108ddfad2a871c7cbd61a085
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3452029Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79264}