Fix mypyc build (#6787)

mypyc doesn't support non-default arguments following default arguments,
even if they are keyword only.

Author: msullivan

mypy/newsemanal/semanal.py

@@ -4351,7 +4351,7 @@ def name_not_defined(self, name: str, ctx: Context, namespace: Optional[str] = N
             self.note(hint, ctx)
 
     def already_defined(self, name: str, ctx: Context,
-                        original_ctx: Optional[Union[SymbolTableNode, SymbolNode]] = None, *,
+                        original_ctx: Optional[Union[SymbolTableNode, SymbolNode]],
                         noun: str) -> None:
         if isinstance(original_ctx, SymbolTableNode):
             node = original_ctx.node  # type: Optional[SymbolNode]

mypy/semanal.py

@@ -3788,7 +3788,7 @@ def name_not_defined(self, name: str, ctx: Context) -> None:
             self.note(hint, ctx)
 
     def already_defined(self, name: str, ctx: Context,
-                        original_ctx: Optional[Union[SymbolTableNode, SymbolNode]] = None, *,
+                        original_ctx: Optional[Union[SymbolTableNode, SymbolNode]],
                         noun: str) -> None:
         if isinstance(original_ctx, SymbolTableNode):
             node = original_ctx.node