Change subclass to function wrapper

This avoids mypy complaining that we need to provide a generic
argument to Popen, which we cannot acctually do as the implementation
of Popen does not inherit from typing.Generic.

jedi/inference/compiled/subprocess/__init__.py

@@ -29,8 +29,7 @@ _MAIN_PATH = os.path.join(os.path.dirname(__file__), '__main__.py')
 PICKLE_PROTOCOL = 4
 
 
-class _GeneralizedPopen(subprocess.Popen):
-    def __init__(self, *args, **kwargs):
+def _GeneralizedPopen(*args, **kwargs):
     if os.name == 'nt':
         try:
             # Was introduced in Python 3.7.
@@ -41,7 +40,8 @@ class _GeneralizedPopen(subprocess.Popen):
     # The child process doesn't need file descriptors except 0, 1, 2.
     # This is unix only.
     kwargs['close_fds'] = 'posix' in sys.builtin_module_names
-        super().__init__(*args, **kwargs)
+
+    return subprocess.Popen(*args, **kwargs)
 
 
 def _enqueue_output(out, queue_):