Preview crashes on await (yield)

[jakkdl]

Describe the bug
black --preview crashes on seeing await (yield)
This is certainly not good code or anything, but is code we have in one of our test files in flake8-trio. Non-preview black has no issues with it.

To Reproduce

For example, take this code:

async def foo():
    await (yield)

And run it with these arguments:

$ black --preview myfile.py 

The resulting error is:

error: cannot format myfile.py: blib2to3.pytree.Node object expected; got blib2to3.pytree.Leaf

Oh no! 💥 💔 💥
1 file failed to reformat.

Expected behavior

Not crashing

Environment

$ black --version
black, 22.12.0 (compiled: yes)
Python (CPython) 3.11.0
$ python --version
Python 3.11.0
$ uname -sro
Linux 6.1.1-arch1-1 GNU/Linux

[JelleZijlstra]

Thanks! We'll fix this before the stable release.

[JelleZijlstra]

Note this only repros with mypyc enabled. This is the stack trace (from black -v):

Traceback (most recent call last):
  File "src/black/__init__.py", line 770, in reformat_one
  File "src/black/__init__.py", line 810, in format_file_in_place
  File "src/black/__init__.py", line 926, in format_file_contents
  File "src/black/__init__.py", line 1073, in format_str
  File "src/black/__init__.py", line 1100, in _format_str_once
  File "src/black/nodes.py", line 169, in visit
  File "src/black/linegen.py", line 139, in visit_default
  File "src/black/nodes.py", line 175, in visit_default
  File "src/black/nodes.py", line 167, in visit
  File "src/black/linegen.py", line 265, in visit_async_stmt
  File "src/black/nodes.py", line 167, in visit
  File "src/black/linegen.py", line 222, in visit_suite
  File "src/black/linegen.py", line 139, in visit_default
  File "src/black/nodes.py", line 175, in visit_default
  File "src/black/nodes.py", line 167, in visit
  File "src/black/linegen.py", line 248, in visit_simple_stmt
  File "src/black/linegen.py", line 139, in visit_default
  File "src/black/nodes.py", line 175, in visit_default
  File "src/black/nodes.py", line 167, in visit
  File "src/black/linegen.py", line 294, in visit_power
  File "src/black/linegen.py", line 1075, in remove_await_parens
TypeError: blib2to3.pytree.Node object expected; got blib2to3.pytree.Leaf

I think I found the cause; it's a bad cast. I'll propose a fix.

[jakkdl]

Nice and quick, thanks!