Move implementation of fract(float) into driver/runtime.

Move the implementation of the float variant of fract from rs_math.rsh
into driver/runtime. The old implementation remains in place for older
versions, and the move occurs only for API level >= 24.

Signed-off-by: Verena Beckham <verena@codeplay.com>
Change-Id: Id94e7191604d5ccaee41b6634731ee997bf01983
3 files changed