Use correct register class for refs

LoadValue requires thar ref location should reguest kRefReg
register class. The patch fixes GenFilledNewArray to specify
the register class correctly.

This is a fix for the crash of dex2oat on 412-new-array unit test.
This is a second attempt with an additional fix for arm64.

Change-Id: I9f0bb098cd1d1721ef03e8976c1460f8fa49aa2a
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>