Move mirror::Class to use ObjPtr

Leave the return types as non ObjPtr for now. Fixed moving GC bugs
in tests.

Test: test-art-host

Bug: 31113334

Change-Id: I5da1b5ac55dfbc5cc97a64be2c870ba9f512d9b0
diff --git a/runtime/class_linker_test.cc b/runtime/class_linker_test.cc
index e514112..6279717 100644
--- a/runtime/class_linker_test.cc
+++ b/runtime/class_linker_test.cc
@@ -211,13 +211,13 @@
     EXPECT_TRUE(array->ShouldHaveEmbeddedVTable());
     EXPECT_EQ(2, array->GetIfTableCount());
     ASSERT_TRUE(array->GetIfTable() != nullptr);
-    mirror::Class* direct_interface0 = mirror::Class::GetDirectInterface(self, array, 0);
+    ObjPtr<mirror::Class> direct_interface0 = mirror::Class::GetDirectInterface(self, array, 0);
     EXPECT_TRUE(direct_interface0 != nullptr);
     EXPECT_STREQ(direct_interface0->GetDescriptor(&temp), "Ljava/lang/Cloneable;");
-    mirror::Class* direct_interface1 = mirror::Class::GetDirectInterface(self, array, 1);
+    ObjPtr<mirror::Class> direct_interface1 = mirror::Class::GetDirectInterface(self, array, 1);
     EXPECT_STREQ(direct_interface1->GetDescriptor(&temp), "Ljava/io/Serializable;");
     mirror::Class* array_ptr = array->GetComponentType();
-    EXPECT_EQ(class_linker_->FindArrayClass(self, &array_ptr), array.Get());
+    EXPECT_OBJ_PTR_EQ(class_linker_->FindArrayClass(self, &array_ptr), array.Get());
 
     PointerSize pointer_size = class_linker_->GetImagePointerSize();
     mirror::Class* JavaLangObject =