cppgc: Add early bailout to write barrier

This bailout applies only when young generation is disabled.
Otherwise, getting the caged heap is required and the global load
bailout becomes redundant.

Bug: chromium:1056170, chromium:1239030
Change-Id: I826b355f4356a5c20812d9c8bf6ebc7ea0997b8a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3173685
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77006}

include/cppgc/internal/write-barrier.h

@@ -214,6 +214,11 @@ struct WriteBarrierTypeForCagedHeapPolicy::ValueModeDispatch<
   static V8_INLINE WriteBarrier::Type Get(const void* slot, const void* value,
                                           WriteBarrier::Params& params,
                                           HeapHandleCallback) {
+#if !defined(CPPGC_YOUNG_GENERATION)
+    if (V8_LIKELY(!WriteBarrier::IsAnyIncrementalOrConcurrentMarking())) {
+      return SetAndReturnType<WriteBarrier::Type::kNone>(params);
+    }
+#endif  // !CPPGC_YOUNG_GENERATION
     bool within_cage = TryGetCagedHeap(slot, value, params);
     if (!within_cage) {
       return WriteBarrier::Type::kNone;
@@ -317,7 +322,10 @@ struct WriteBarrierTypeForNonCagedHeapPolicy::ValueModeDispatch<
                                           HeapHandleCallback callback) {
     // The following check covers nullptr as well as sentinel pointer.
     if (object <= static_cast<void*>(kSentinelPointer)) {
-      return WriteBarrier::Type::kNone;
+      return SetAndReturnType<WriteBarrier::Type::kNone>(params);
+    }
+    if (V8_LIKELY(!WriteBarrier::IsAnyIncrementalOrConcurrentMarking())) {
+      return SetAndReturnType<WriteBarrier::Type::kNone>(params);
     }
     if (IsMarking(object, &params.heap)) {
       return SetAndReturnType<WriteBarrier::Type::kMarking>(params);