PY-81926 Don't report using classes overriding __or__ in the Class1 | Class2 notation for unions

It should only be special cases for classes which *metaclasses*
override `__or__` so that this notation is possible.

Other type checkers treat such union of classes overriding
__or__ in their metaclass as Unknown.

(cherry picked from commit c16edee2346582745aa5090c3d8f568a4513afc1)

IJ-CR-176451

(cherry picked from commit 4dfc125bcfc625d1fe5577695e9a75449f40594a)

GitOrigin-RevId: 9f066646863ec321bcace0d2d10efe44a3c12728

python/python-psi-impl/src/com/jetbrains/python/codeInsight/typing/PyTypingTypeProvider.java

@@ -817,11 +817,16 @@ public final class PyTypingTypeProvider extends PyTypeProviderWithCustomContext<
 
   private static boolean typeHasOverloadedBitwiseOr(@NotNull PyType type, @NotNull PyExpression expression,
                                                     @NotNull Context context) {
-    if (type instanceof PyUnionType) return false;
-
-    PyType typeToClass = type instanceof PyClassLikeType ? ((PyClassLikeType)type).toClass() : type;
-    var resolved = typeToClass.resolveMember("__or__", expression, AccessDirection.READ,
-                                             PyResolveContext.defaultContext(context.getTypeContext()));
+    if (!(type instanceof PyClassType classType)) {
+      return false;
+    }
+    TypeEvalContext typeContext = context.getTypeContext();
+    PyClassLikeType metaClassType = classType.getMetaClassType(typeContext, true);
+    if (metaClassType == null) {
+      return false;
+    }
+    var resolved = metaClassType
+      .resolveMember("__or__", expression, AccessDirection.READ, PyResolveContext.defaultContext(typeContext));
     if (resolved == null || resolved.isEmpty()) return false;
 
     return StreamEx.of(resolved)

python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java

@@ -2962,6 +2962,20 @@ public class PyTypeHintsInspectionTest extends PyInspectionTestCase {
     doMultiFileTest();
   }
 
+  // PY-81926
+  public void testUnionWithClassOverridingDunderOr() {
+    doTestByText("""
+                   from typing import Self
+                   
+                   class Cls:
+                       def __or__(self, other: Self) -> Self:
+                           return self
+                   
+                   def foo(arg: Cls | None) -> None:
+                       print(arg)
+                   """);
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {