- Removed the kWatchedBit and the associated weak property handling

runtime/vm/snapshot.h

Index: runtime/vm/snapshot.h
diff --git a/runtime/vm/snapshot.h b/runtime/vm/snapshot.h
index da26ca11dc62aad0fa63e769fd41b46ec7f5c3a8..601eba53e172e54c056493899ef3398720a53c6b 100644
--- a/runtime/vm/snapshot.h
+++ b/runtime/vm/snapshot.h
@@ -297,7 +297,6 @@ class BaseReader {
 
   intptr_t ReadTags() {
     const intptr_t tags = static_cast<intptr_t>(Read<int8_t>()) & 0xff;
-    ASSERT(SerializedHeaderTag::decode(tags) != kObjectId);
     return tags;
   }
 
@@ -757,7 +756,6 @@ class BaseWriter : public StackResource {
   }
 
   void WriteTags(intptr_t tags) {
-    ASSERT(SerializedHeaderTag::decode(tags) != kObjectId);
     const intptr_t flags = tags & 0xff;
     Write<int8_t>(static_cast<int8_t>(flags));
   }