Fix broken docs (#124940)

These were causing doctest to be unhappy.

In particular the doc from #124496 caused #124771 to fail "trunk / win-vs2019-cpu-py3 / test" to fail when pushing. Not sure why it wasn't a problem on the original PR.

Testing:

`./test/run_doctests.sh`:
  before:
```
=== 4 warnings in 11.21 seconds ===
```
  after:
```
===  in 11.11 seconds ===
```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/124940
Approved by: https://github.com/zou3519, https://github.com/atalman, https://github.com/huydhn

.github/workflows/_win-test.yml

@@ -92,7 +92,7 @@ jobs:
           retry_wait_seconds: 30
           command: |
             set -eu
-            python3 -m pip install rockset==1.0.3
+            python3 -m pip install rockset==1.0.3 'xdoctest>=1.1.0'
 
       - name: Start monitoring script
         id: monitor-script

torch/compiler/__init__.py

@@ -166,9 +166,9 @@ def is_compiling() -> bool:
 
         >>> def forward(self, x):
         >>>     if not torch.compiler.is_compiling():
-        >>>        ...logic that is not needed in a compiled/traced graph...
+        >>>        pass # ...logic that is not needed in a compiled/traced graph...
         >>>
-        >>>     ...rest of the function...
+        >>>     # ...rest of the function...
     """
     if torch.jit.is_scripting():
         return False
@@ -186,8 +186,8 @@ def is_dynamo_compiling() -> bool:
 
         >>> def forward(self, x):
         >>>     if not torch.compiler.is_dynamo_compiling():
-        >>>        ...logic that is not needed in a TorchDynamo-traced graph...
+        >>>        pass # ...logic that is not needed in a TorchDynamo-traced graph...
         >>>
-        >>>     ...rest of the function...
+        >>>     # ...rest of the function...
     """
     return False

torch/library.py

@@ -849,11 +849,11 @@ def opcheck(
         >>> def _(x, y):
         >>>     return torch.empty_like(x)
         >>>
-        >>> def setup_context(ctx, inputs, output)
+        >>> def setup_context(ctx, inputs, output):
         >>>     y, = inputs
         >>>     ctx.y = y
         >>>
-        >>> def backward(ctx, grad)
+        >>> def backward(ctx, grad):
         >>>     return grad * ctx.y, None
         >>>
         >>> numpy_sin.register_autograd(backward, setup_context=setup_context)

torch/utils/data/_utils/collate.py

@@ -121,7 +121,7 @@ def collate(batch, *, collate_fn_map: Optional[Dict[Union[Type, Tuple[Type, ...]
 
     Examples:
         >>> def collate_tensor_fn(batch, *, collate_fn_map):
-        >>> # Extend this function to handle batch of tensors
+        ...     # Extend this function to handle batch of tensors
         ...     return torch.stack(batch, 0)
         >>> def custom_collate(batch):
         ...     collate_map = {torch.Tensor: collate_tensor_fn}