Keep dex files live in class table

The DexFile.loadClass API allows callers to load classes using a
dex file without having that dex file owned by the specified class
loader. We now add the dex file to the class table to make sure it
stays live until the class loader is unreachable.

Fixes interpreter gcstress test 087 with 64 bit.

Bug: 22720414
Change-Id: Ia4341149f45b6293312f8b275c7a68cea179f718
7 files changed