Handle operators consistently

Author: ilevkivskyi

mypy/checker.py

@@ -3639,7 +3639,7 @@ def lvalue_type_from_base(
         mx = MemberContext(
             is_lvalue=setter_type,
             is_super=False,
-            is_operator=False,
+            is_operator=mypy.checkexpr.is_operator_method(expr_name),
             original_type=self_type,
             context=expr_node,
             chk=self,

test-data/unit/check-functools.test

@@ -28,8 +28,8 @@ from typing import Any, Callable, ClassVar
 
 @total_ordering
 class Ord:
-    __eq__: ClassVar[Callable[[Any, object], bool]] = lambda self, other: False
-    __lt__: ClassVar[Callable[[Any, "Ord"], bool]] = lambda self, other: False
+    __eq__: Callable[[Any, object], bool] = lambda self, other: False
+    __lt__: Callable[[Any, "Ord"], bool] = lambda self, other: False
 
 reveal_type(Ord() < Ord())  # N: Revealed type is "builtins.bool"
 reveal_type(Ord() <= Ord())  # N: Revealed type is "builtins.bool"