Log backward graph compilation metrics (#126629)
Summary:
Fixes #125313
Compilation metric logs for the code example at #125313:
```
%s CompilationMetrics(compile_id='0/0', frame_key='1', co_name='forward', co_filename='/data/users/ybliang/debug/debug2.py', co_firstlineno=10, cache_size=0, accumulated_cache_size=0, guard_count=11, shape_env_guard_count=0, graph_op_count=1, graph_node_count=3, graph_input_count=1, start_time=1716247236.6165977, entire_frame_compile_time_s=7.926939964294434, backend_compile_time_s=7.887059926986694, inductor_compile_time_s=4.108498811721802, code_gen_time_s=3.97833514213562, fail_type=None, fail_reason=None, fail_user_frame_filename=None, fail_user_frame_lineno=None, non_compliant_ops=set(), compliant_custom_ops=set(), restart_reasons={"'skip function graph_break in file /home/ybliang/local/pytorch/torch/_dynamo/decorators.py'"}, dynamo_time_before_restart_s=0.025330543518066406, has_guarded_code=True, is_fwd=True)
%s CompilationMetrics(compile_id='1/0', frame_key='2', co_name='torch_dynamo_resume_in_forward_at_12', co_filename='/data/users/ybliang/debug/debug2.py', co_firstlineno=12, cache_size=0, accumulated_cache_size=0, guard_count=10, shape_env_guard_count=0, graph_op_count=2, graph_node_count=5, graph_input_count=1, start_time=1716247244.544928, entire_frame_compile_time_s=0.10148310661315918, backend_compile_time_s=0.08753013610839844, inductor_compile_time_s=0.03691983222961426, code_gen_time_s=0.022417306900024414, fail_type=None, fail_reason=None, fail_user_frame_filename=None, fail_user_frame_lineno=None, non_compliant_ops=set(), compliant_custom_ops=set(), restart_reasons=set(), dynamo_time_before_restart_s=0.0, has_guarded_code=True, is_fwd=True)
tensor([[-0.1622, -0.0000, -0.0000, 0.5643, -0.0000, 0.0000, -0.5087, 0.0914,
-0.0000, -0.0421]], grad_fn=<CompiledFunctionBackward>)
%s CompilationMetrics(compile_id='1/0', frame_key=None, co_name=None, co_filename=None, co_firstlineno=None, cache_size=None, accumulated_cache_size=None, guard_count=None, shape_env_guard_count=None, graph_op_count=None, graph_node_count=None, graph_input_count=None, start_time=None, entire_frame_compile_time_s=None, backend_compile_time_s=None, inductor_compile_time_s=0.026738643646240234, code_gen_time_s=0.016446352005004883, fail_type=None, fail_reason=None, fail_user_frame_filename=None, fail_user_frame_lineno=None, non_compliant_ops=None, compliant_custom_ops=None, restart_reasons=None, dynamo_time_before_restart_s=None, has_guarded_code=None, is_fwd=False)
%s CompilationMetrics(compile_id='0/0', frame_key=None, co_name=None, co_filename=None, co_firstlineno=None, cache_size=None, accumulated_cache_size=None, guard_count=None, shape_env_guard_count=None, graph_op_count=None, graph_node_count=None, graph_input_count=None, start_time=None, entire_frame_compile_time_s=None, backend_compile_time_s=None, inductor_compile_time_s=0.14563536643981934, code_gen_time_s=0.08652091026306152, fail_type=None, fail_reason=None, fail_user_frame_filename=None, fail_user_frame_lineno=None, non_compliant_ops=None, compliant_custom_ops=None, restart_reasons=None, dynamo_time_before_restart_s=None, has_guarded_code=None, is_fwd=False)
```
X-link: https://github.com/pytorch/pytorch/pull/126629
Approved by: https://github.com/ezyang
Reviewed By: atalman
Differential Revision: D58109694
Pulled By: yanboliang
fbshipit-source-id: ae567d7554cbc8e610e5cf68718d3a6a6ee8be67
