[jdk15u-dev] RFR: 8253421: Initialize JFR trace-IDs with zero

[Ekaterina Vergizova]

I'd like to backport JDK-8253421 to 15u as a prerequisite for JDK-8260589.
The patch applies cleanly.
Tested with tier1 and jdk/jfr tests.

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Commit messages:
 - Backport 0c287de4f61f6f4780c9dad6ed45876c9eaa55f8

Changes: https://git.openjdk.java.net/jdk15u-dev/pull/126/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk15u-dev&pr=126&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253421
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk15u-dev/pull/126.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk15u-dev pull/126/head:pull/126

PR: https://git.openjdk.java.net/jdk15u-dev/pull/126