CopyReplace      4838 src/objects.cc     maybe_descriptors = old_descriptors->CopyReplace(descriptor, index);
CopyReplace      4851 src/objects.cc       instance_descriptors()->CopyReplace(descriptor, index);
CopyReplace      2572 src/objects.h    MUST_USE_RESULT MaybeObject* CopyReplace(Descriptor* descriptor,