RFR: Remove perf event modifiers to validate if they are supported

[Ian Rogers]

An alternative to cycles:p is to use cycles:P (note the case) which
means use the maximum precision level that is supported. It will give
more accurate sampling than cycles:p when possible and works with perf
stat:
```
$ sudo perf stat -e cycles:P true

 Performance counter stats for 'true':

           900,546      cycles:P

       0.001261127 seconds time elapsed

       0.001401000 seconds user
       0.000000000 seconds sys
```

Thanks,
Ian


On Fri, May 31, 2024 at 10:53 AM Galder Zamarreño <galder at openjdk.org> wrote:
>
> Fixes https://bugs.openjdk.org/browse/CODETOOLS-7903740
>
> -------------
>
> Commit messages:
>  - Remove perf event modifiers to validate if they are supported
>
> Changes: https://git.openjdk.org/jmh/pull/132/files
>   Webrev: https://webrevs.openjdk.org/?repo=jmh&pr=132&range=00
>   Stats: 8 lines in 1 file changed: 7 ins; 0 del; 1 mod
>   Patch: https://git.openjdk.org/jmh/pull/132.diff
>   Fetch: git fetch https://git.openjdk.org/jmh.git pull/132/head:pull/132
>
> PR: https://git.openjdk.org/jmh/pull/132