[libc][math] Improve performance test framework (llvm#134501)

- Merges `BinaryOpSingleOutputPerf.h` and
`SingleInputSingleOutputPerf.h` files into a unified `PerfTest.h` and
update all performance tests to use this.
- Improve the output printed to log file for tests.
- Removes unused `run_diff` method and redundant `run_perf` call in
`BINARY_INPUT_SINGLE_OUTPUT_PERF_EX` (previously
`BINARY_OP_SINGLE_OUTPUT_PERF_EX`)
- Change `BINARY_INPUT_SINGLE_OUTPUT_PERF_EX` and
`SINGLE_INPUT_SINGLE_OUTPUT_PERF` to not define `main`

Author: meltq