ART: Lock an arg reg in GenInlinedGet
ART: Lock an arg reg in GenInlinedGet

Must lock an explicit target register so that it doesn't get used
for a temp and clobbered.

Bug: 16352802
Change-Id: I9e4ac76f92460cdbe59392989d12f8d0321cc624

treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst,treadstoneproject/artinst