[jdk21] RFR: 8308103: Massive (up to ~30x) increase in C2 compilation time since JDK 17

[Tobias Hartmann]

Backport of [JDK-8308103](https://bugs.openjdk.java.net/browse/JDK-8308103). Applies cleanly.

Thanks,
Tobias

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Commit messages:
 - 8308103: Massive (up to ~30x) increase in C2 compilation time since JDK 17

Changes: https://git.openjdk.org/jdk21/pull/141/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21&pr=141&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8308103
  Stats: 70 lines in 2 files changed: 69 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk21/pull/141.diff
  Fetch: git fetch https://git.openjdk.org/jdk21.git pull/141/head:pull/141

PR: https://git.openjdk.org/jdk21/pull/141