[wasm] Fix flaky failure in tier-down-to-liftoff test

Since the {kFinishedRecompilation} event can happen either before or
after the {kFinishedTopTierCompilation} event, we should not check it's
order relative to the other events.

R=ahaas@chromium.org

Bug: v8:10086
Change-Id: I880700b514c7c2238a0eb7791875bf0b81c64e97
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2020779Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65999}

src/wasm/module-compiler.cc

@@ -1707,7 +1707,10 @@ class AsyncCompileJob::CompilationStateCallback {
         }
         break;
       case CompilationEvent::kFinishedRecompilation:
-        break;
+        // This event can happen either before or after
+        // {kFinishedTopTierCompilation}, hence don't remember this in
+        // {last_event_}.
+        return;
       default:
         UNREACHABLE();
     }