Add BaseDatabaseWrapper.operations (#1119)

django-stubs/db/backends/base/base.pyi

@@ -1,6 +1,6 @@
 from contextlib import contextmanager
 from datetime import tzinfo
-from typing import Any, Callable, Dict, Generator, Iterator, List, Optional, Set, Tuple, Type, TypeVar
+from typing import Any, Callable, Dict, Generator, Iterator, List, MutableMapping, Optional, Set, Tuple, Type, TypeVar
 
 from django.db.backends.base.client import BaseDatabaseClient
 from django.db.backends.base.creation import BaseDatabaseCreation
@@ -53,6 +53,7 @@ class BaseDatabaseWrapper:
     introspection: BaseDatabaseIntrospection = ...
     ops: BaseDatabaseOperations = ...
     validation: BaseDatabaseValidation = ...
+    operators: MutableMapping[str, str] = ...
     def __init__(self, settings_dict: Dict[str, Any], alias: str = ...) -> None: ...
     def ensure_timezone(self) -> bool: ...
     @property