Fix moving GC bug in cloning finalizable objects

It is not safe to have thread suspension in the PreFenceVisitor. The fix is
to add the finalizer reference in the caller.

Test: art/tools/run-libcore-tests.sh '--mode=host' '--variant=X32' --debug

Bug: 31113334

Change-Id: I1e4650f8b75408a3d07e2c51ac334ff98552cfb5
3 files changed