Add start event metadata to collected metadata for PT2 Compile Events

Summary:
X-link: pytorch/pytorch#139289

We should be logging metadata from event starts to PT2 Compile Events too.
ghstack-source-id: 250444771

Reviewed By: oulgen

Differential Revision: D65070086

fbshipit-source-id: 63b934bff4254871e15a615e5aa47112b032b143

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -1023,6 +1023,8 @@ def log_event_start(
             metadata,
         )
         self.get_stack().append(event_name)
+        # Add metadata from start event
+        self.add_event_data(event_name, **metadata)
 
     def reset(self) -> None:
         # We this on every compile in case a compile crashes or restarts and we haven't