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

@@ -29,19 +29,19 @@ _MAIN_PATH = os.path.join(os.path.dirname(__file__), '__main__.py')
 PICKLE_PROTOCOL = 4
 
 
-class _GeneralizedPopen(subprocess.Popen):
-    def __init__(self, *args, **kwargs):
-        if os.name == 'nt':
-            try:
-                # Was introduced in Python 3.7.
-                CREATE_NO_WINDOW = subprocess.CREATE_NO_WINDOW
-            except AttributeError:
-                CREATE_NO_WINDOW = 0x08000000
-            kwargs['creationflags'] = CREATE_NO_WINDOW
-        # 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)
+def _GeneralizedPopen(*args, **kwargs):
+    if os.name == 'nt':
+        try:
+            # Was introduced in Python 3.7.
+            CREATE_NO_WINDOW = subprocess.CREATE_NO_WINDOW
+        except AttributeError:
+            CREATE_NO_WINDOW = 0x08000000
+        kwargs['creationflags'] = CREATE_NO_WINDOW
+    # 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
+
+    return subprocess.Popen(*args, **kwargs)
 
 
 def _enqueue_output(out, queue_):