RFR: 8315149: Add hsperf counters for CPU time of internal GC threads [v32]

[Jonathan Joo]

> 8315149: Add hsperf counters for CPU time of internal GC threads

Jonathan Joo has updated the pull request incrementally with one additional commit since the last revision:

  Use 64-bit atomic add for incrementing counters

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15082/files
  - new: https://git.openjdk.org/jdk/pull/15082/files/b57aa467..ebafa2b5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15082&range=31
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15082&range=30-31

  Stats: 13 lines in 1 file changed: 0 ins; 13 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15082.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15082/head:pull/15082

PR: https://git.openjdk.org/jdk/pull/15082