Improve support for backwards hooks (#119525)

Summary:
X-link: pytorch/pytorch#119525
Approved by: https://github.com/yanboliang, https://github.com/anijain2305

Reviewed By: huydhn

Differential Revision: D53634801

Pulled By: jansel

fbshipit-source-id: d18819e331cd408f099ef5101cdbe9bc3d1ae172

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -50,6 +50,7 @@
     ValuesView,
 )
 
+from ..utils.hooks import RemovableHandle
 
 try:
     import numpy as np
@@ -2494,3 +2495,11 @@ def inner_compiler(gm_, example_inputs_):
             yield ctx
     else:
         yield
+
+
+def invalid_removeable_handle():
+    # need a subclass so weakref works
+    class Invalid(dict):  # type: ignore[type-arg]
+        pass
+
+    return RemovableHandle(Invalid())