RFR: JDK-8329605: hs errfile generic events - introduce sections for Frequent/NotFrequent Events [v2]

[Matthias Baesken]

> Currently the 'generic' hs_errfile Events message log (filled  by Events::log) is rather flooded by messages for memory protection operations. Those seem to occur quite often and move out other less frequent events, because the number of entries in the log is limited.
> It might be better to separate the frequent and less frequent events into 2 sections. The memory protection events would go into the frequent events section.
> The mentioned memory protection operations related entries look like this :
> Event: 0.178 Protecting memory [0x000000016ebf0000,0x000000016ebfc000] with protection modes 0

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  Introduce separate nmethod flush log

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18626/files
  - new: https://git.openjdk.org/jdk/pull/18626/files/27a319be..63ccaffb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18626&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18626&range=00-01

  Stats: 17 lines in 3 files changed: 16 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18626.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18626/head:pull/18626

PR: https://git.openjdk.org/jdk/pull/18626