fix test_functional_call_sequential_params_and_buffers expectation on Windows (#134394)

Summary:
This UT actual code only one empty line wrap difference(`linear` and `add`) between Windows/Linux, and the context is right.
Reproduce UTs:
```cmd
pytest test\dynamo\test_higher_order_ops.py -v -k test_functional_call_sequential_params_and_buffers
```

We can add `empty_line_normalizer` to fix it.

```cmd
______________________________________________________________________________________________ FuncTorchHigherOrderOpTests.test_functional_call_sequential_params_and_buffers _______________________________________________________________________________________________
Traceback (most recent call last):
  File "D:\xu_git\dnnl_cb\pytorch\test\dynamo\test_higher_order_ops.py", line 3676, in test_functional_call_sequential_params_and_buffers
    self.assertExpectedInline(
  File "C:\Users\Xuhan\.conda\envs\win_mkl_static\lib\site-packages\torch\testing\_internal\common_utils.py", line 2871, in assertExpectedInline
    return super().assertExpectedInline(actual if isinstance(actual, str) else str(actual), expect, skip + 1)
  File "C:\Users\Xuhan\.conda\envs\win_mkl_static\lib\site-packages\expecttest\__init__.py", line 271, in assertExpectedInline
    self.assertMultiLineEqualMaybeCppStack(expect, actual, msg=help_text)
  File "C:\Users\Xuhan\.conda\envs\win_mkl_static\lib\site-packages\expecttest\__init__.py", line 292, in assertMultiLineEqualMaybeCppStack
    self.assertMultiLineEqual(expect, actual, *args, **kwargs)
  File "C:\Users\Xuhan\.conda\envs\win_mkl_static\lib\unittest\case.py", line 1226, in assertMultiLineEqual
    self.fail(self._formatMessage(msg, standardMsg))
  File "C:\Users\Xuhan\.conda\envs\win_mkl_static\lib\unittest\case.py", line 675, in fail
    raise self.failureException(msg)
AssertionError: 'clas[509 chars]one\n        add: "f32[1, 1]" = linear + l_buf[69 chars],)\n' != 'clas[509 chars]one\n\n        add: "f32[1, 1]" = linear + l_b[71 chars],)\n'
  class GraphModule(torch.nn.Module):
      def forward(self, L_params_l1_weight_: "f32[1, 1]", L_params_l1_bias_: "f32[1]", L_buffers_buffer_: "f32[1]", L_inputs_: "f32[1, 1]"):
          l_params_l1_weight_ = L_params_l1_weight_
          l_params_l1_bias_ = L_params_l1_bias_
          l_buffers_buffer_ = L_buffers_buffer_
          l_inputs_ = L_inputs_

          linear: "f32[1, 1]" = torch._C._nn.linear(l_inputs_, l_params_l1_weight_, l_params_l1_bias_);  l_inputs_ = l_params_l1_weight_ = l_params_l1_bias_ = None
+ <<<< (difference is here )
          add: "f32[1, 1]" = linear + l_buffers_buffer_;  linear = l_buffers_buffer_ = None
          return (add,)
 : To accept the new output, re-run test with envvar EXPECTTEST_ACCEPT=1 (we recommend staging/committing your changes before doing this)

To execute this test, run the following from the base repo dir:
    python test\dynamo\test_higher_order_ops.py FuncTorchHigherOrderOpTests.test_functional_call_sequential_params_and_buffers

This message can be suppressed by setting PYTORCH_PRINT_REPRO_ON_FAILURE=0
========================================================================================================================== short test summary info ==========================================================================================================================
FAILED [0.4275s] test/dynamo/test_higher_order_ops.py::FuncTorchHigherOrderOpTests::test_functional_call_sequential_params_and_buffers - AssertionError: 'clas[509 chars]one\n        add: "f32[1, 1]" = linear + l_buf[69 chars],)\n' != 'clas[509 chars]one\n\n        add: "f32[1, 1]" = linear + l_b[71 chars],)\n'
```

X-link: pytorch/pytorch#134394
Approved by: https://github.com/jansel

Reviewed By: ZainRizvi

Differential Revision: D61829624

fbshipit-source-id: b44a2bd36bf64601263e901e0384a8a45fab6e7a

Co-authored-by: Jason Ansel <jansel@jansel.net>

Author: 2 people

userbenchmark/dynamo/dynamobench/_dynamo/testing.py

@@ -229,6 +229,14 @@ def normalize_gm(gm_str) -> str:
     return remove_trailing_space(strip_comment(gm_str))
 
 
+def empty_line_normalizer(code: str) -> str:
+    """
+    Normalize code: remove empty lines.
+    """
+    normal_code = re.sub(r"[\r\n]+", "\n", code)
+    return normal_code
+
+
 def standard_test(
     self,
     fn,