ART: Split out more cases of Load/StoreRef, volatile as parameter

Splits out more cases of ref registers being loaded or stored. For
code clarity, adds volatile as a flag parameter instead of a separate
method.

On ARM64, continue cleanup. Add flags to print/fatal on size mismatches.

Change-Id: I30ed88433a6b4ff5399aefffe44c14a5e6f4ca4e