RFR: 8325502: JFR: The type of EventSystemProcess::pid should be long

[Denghui Dong]

Hi,

Please review this patch that changes the type of `EventSystemProcess::pid` to `long`

Thanks

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Commit messages:
 - update
 - 8325502: JFR: The type of EventSystemProcess::pid should be long

Changes: https://git.openjdk.org/jdk/pull/17773/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17773&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325502
  Stats: 13 lines in 3 files changed: 1 ins; 6 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/17773.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17773/head:pull/17773

PR: https://git.openjdk.org/jdk/pull/17773