[execution] Limit noise from differing stack traces with fuzzing

Always return an empty string when formatting stack traces with
--correctness-fuzzer-suppressions. In out-of-stack-space situations
it's easy to get different values depending on whether emergency
formatting is chosen or not.

Bug: chromium:1244626
Change-Id: I2f3d1692deae2533b70b62f28b39875e812b4b0c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3132968Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76609}

src/execution/messages.cc

@@ -297,6 +297,9 @@ class V8_NODISCARD PrepareStackTraceScope {
 MaybeHandle<Object> ErrorUtils::FormatStackTrace(Isolate* isolate,
                                                  Handle<JSObject> error,
                                                  Handle<Object> raw_stack) {
+  if (FLAG_correctness_fuzzer_suppressions) {
+    return isolate->factory()->empty_string();
+  }
   DCHECK(raw_stack->IsFixedArray());
   Handle<FixedArray> elems = Handle<FixedArray>::cast(raw_stack);