This adds a test which I suspected would fail, but luckily it doesn't.
The idea is to catch a proper wasm exception in JS, then construct a new
exception, but set the catched exception as the prototype. My suspicion
was that we would still handle that new exception like a wasm exception,
since the `WasmExceptionGetTag` and `WasmExceptionGetValues` runtime
functions to a standard property lookup, which includes a prototype
walk.
Interestingly, the prototype walk is already skipped automatically when
loading private symbols, so the implementation already supports this
case correctly.
Let's still add this test to have coverage for this case.

R=jkummerow@chromium.org
CC=aheejin@chromium.org

Bug: v8:8091
Change-Id: Idf9944cf47f96cca38e9678e9200bf03a39ea126
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2167438Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67391}