Add a workload for powf. This is a reduced trace based on 2.3 billion
samples extracted from wrf. The distribution of values, in particular
frequency of commonly used operands is the same as in the full trace.
* benchtests/powf-inputs: Add reduced trace from wrf.
Add powf() bench test with input which covers these cases:
- positive base to positive exponent
- exponent 0
- negative base to even exponent
- exponent 1
- exponent -1
- squared
- squareroot
- 1 to negative exponent
- -1 to negative exponent
- base 0
- -1 to even exponent
- small base
- small exponent
* benchtests/Makefile (bench-math): Add powf.
* benchtests/powf-inputs: New file.