ObjPtr<>-ify ArtMethod and mirror::Method.

And clean up some forgotten things after old CLs.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 31113334
Change-Id: I8af0e845c24d674d0efab21d80c29949b1cc0593
diff --git a/patchoat/patchoat.cc b/patchoat/patchoat.cc
index 97b315e..9b9cfba 100644
--- a/patchoat/patchoat.cc
+++ b/patchoat/patchoat.cc
@@ -1072,7 +1072,7 @@
   copy->CopyFrom(object, pointer_size);
   // Just update the entry points if it looks like we should.
   // TODO: sanity check all the pointers' values
-  copy->SetDeclaringClass(RelocatedAddressOfPointer(object->GetDeclaringClass()));
+  copy->SetDeclaringClass(RelocatedAddressOfPointer(object->GetDeclaringClass().Ptr()));
   copy->SetEntryPointFromQuickCompiledCodePtrSize(RelocatedAddressOfPointer(
       object->GetEntryPointFromQuickCompiledCodePtrSize(pointer_size)), pointer_size);
   // No special handling for IMT conflict table since all pointers are moved by the same offset.