[runtime] Fix serialization of EmbedderDataArray

Currently serialization of external pointers stored in EmbedderDataArray
is not supported but such a functionality was never needed before.

Bug: v8:13007, v8:12949
Change-Id: I56dc33592c1410ac9e234c60ef79db92a4e96a0f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3740724
Auto-Submit: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81497}

src/snapshot/serializer.cc

@@ -1084,6 +1084,9 @@ void Serializer::ObjectSerializer::VisitExternalPointer(
     // Serialization of external references in other objects is handled
     // elsewhere or not supported.
     DCHECK(
+        // Serialization of external pointers stored in EmbedderDataArray
+        // is not supported yet, mostly because it's not used.
+        InstanceTypeChecker::IsEmbedderDataArray(instance_type) ||
         // See ObjectSerializer::SerializeJSTypedArray().
         InstanceTypeChecker::IsJSTypedArray(instance_type) ||
         // See ObjectSerializer::SerializeJSArrayBuffer().