Mostly src/codegen, src/compiler, src/interpreter, src/libplatform.

Drive-by: Remove some unreachable code.

Bug: v8:13006
Change-Id: I1a9467f7e42531c545f660d35416c388e8ef9d3c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3749193
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81613}