ART: Fix Quick-style LR vs PC core spill mask bug

It's always been a bug that Quick marked PC as spilled instead of
LR. The root cause was a mutation of the spill mask at frame exit,
when LR is being restored into PC to return. A local should have
been used to keep the actual spill mask safe and sound.

This has only worked because nobody ever uses LR, even after long
jumps for exception dispatch. However, single-frame deoptimization
needs this to work, and I'd rather fix this than being forced to
have machine-specific fixups.

Also fix in optimizing, and bump the oat version.

Change-Id: Ib032a533408bf464097fc96dcbfc5b6a68bf59a1