1) Inlining functions that contain stringref operations require builtin
   calls to be marked as kNoThrow appropriately (or have exception
   handling support in the graph).
2) Some overly-large inputs for string creation hit DCHECKs before
   getting to the places where they would have thrown an orderly
   exception.
3) We still had a known issue that some exceptions thrown by JS-focused
   code were erroneously catchable by Wasm.
4) When string.concat attempted to create a too-long string, it ran into
   a DCHECK because we didn't clear the "thread in wasm" flag.
5) The builtin call for string.concat was erroneously marked as
   kEliminatable, which could cause the trap get eliminated.

Bug: v8:12868
Change-Id: Iad3ada0e2465bfd8f3d00bb064c32049d6b19d87
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3902522
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Andy Wingo <wingo@igalia.com>
Reviewed-by: Andy Wingo <wingo@igalia.com>
Cr-Commit-Position: refs/heads/main@{#83292}