This is a reland of fab754ff.
The lock-order inversion is fixed by putting the old code into the
surrounding WasmCodeRefScope such that it gets deleted only after
releasing the mutex.

Original change's description:
> [wasm][debug] Cache debugging code
>
> This adds a little cache for debugging code, including stepping code.
> Especially in stepping, we are currently repeatedly recompiling the same
> function, because whenever we pause (after every step) we clear
> stepping, only to reinstantiate it if the user continues stepping.
> Especially in source-level stepping this is wasteful, because stepping
> over a single line of C++ code can execute hundreds or thousands of
> steps in wasm.
>
> R=thibaudm@chromium.org
>
> Bug: chromium:1172299
> Change-Id: Id59a26cc67a5bf4a2d3cf6b1e8f14a8b1c73712c
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2732015
> Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#73162}

Bug: chromium:1172299
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_tsan_isolates_rel_ng
Change-Id: Ic2f92e2758e78dc4912021cd17267a4da563c0a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2732675Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73188}