As a short-term mitigation for the abort() crash that happens
when the g_thread_in_wasm_code flag is set while we attempt to
free a Wasm code object as part of a GC cycle, clear the flag
in Runtime_AllocateInYoungGeneration. (The ...OldGeneration
counterpart is not affected because Wasm code does not request
pretenured allocations currently.)

Bug: chromium:1236668
Change-Id: I97ab9f67935de9aaeca0815e374bdfd8076acf6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3110195Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76423}