[jdk21u] RFR: 8308103: Massive (up to ~30x) increase in C2 compilation time since JDK 17

[Goetz Lindenmaier]

I backport this for parity with 17.0.10-oracle.

The backport deferral was meant for 21, not 21u.  After it being backported to 21.0.10-oracle, 
the risk of bringing it to 21 should be acceptable as this will have much less exposure.

Test passes (including 8312440).  Will run it through SAPs testing.

Will make dependent PR for JDK-8312440.

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Commit messages:
 - Backport c6ab9c2905203e1ec897b3404f9179ff975d0054

Changes: https://git.openjdk.org/jdk21u/pull/199/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=199&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/jdk21u/pull/199.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/199/head:pull/199

PR: https://git.openjdk.org/jdk21u/pull/199