Delegate long-to-float type conversions to the runtime on ARM.

On ARM, translate long-to-float type conversions (from both
Quick and Optimizing) as calls to the runtime routine
art_l2f, instead of generating ad hoc code, so as to improve
the precision of the conversions.

Bug: 20413424
Change-Id: I8c414ee1c6f4ff1f32ee78f75734cfd3cf579f71
8 files changed