RFR: 8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate [v2]

[Long Yang]

> hi
> 
> I would like to fix this.
> 
> As the description in [JDK-8326446](https://bugs.openjdk.org/browse/JDK-8326446).
> JFR uses task_info() with flavor TASK_ABSOLUTETIME_INFO to read User and System time is not reliable on Apple m1.
> 
> Libc provides the [times](https://man7.org/linux/man-pages/man2/times.2.html) function, which uses TASK_BASIC_INFO_COUNT and TASK_THREAD_TIMES_INFO_COUNT. It will also return the real time of the process, and the time unit is the same, which is suitable for solving this problem.
> 
> I ran test/jdk/jdk/jfr/event/os/TestCPULoad.java and passed.
> 
> I would appreciate it if you could review this.

Long Yang has updated the pull request incrementally with one additional commit since the last revision:

  update copyright header

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/17976/files
  - new: https://git.openjdk.org/jdk/pull/17976/files/20a3e526..4cf1dba3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17976&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17976&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17976.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17976/head:pull/17976

PR: https://git.openjdk.org/jdk/pull/17976