Use proper sources for constructing dataclass defaults (#157993)

Summary:
Partially fixes pytorch/pytorch#154009

X-link: pytorch/pytorch#157993
Approved by: https://github.com/williamwen42, https://github.com/anijain2305

Reviewed By: wdvr

Differential Revision: D78599676

fbshipit-source-id: 06baa54a73d6e8bbad7faf2f167425691658aee5

Author: mlazos

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -2572,6 +2572,10 @@ def tuple_iterator_getitem(it, index):
     return obj[start + index]
 
 
+def dataclass_fields(cls):
+    return torch._dynamo.disable(dataclasses.fields)(cls)
+
+
 iter_next = next