[jdk21u-dev] RFR: 8318468: compiler/tiered/LevelTransitionTest.java fails with -XX:CompileThreshold=100 -XX:TieredStopAtLevel=1

[Aleksey Shipilev]

Clean backport to improve test stability and better parity.

Additional testing:
 - [x] Affected test fails without the patch (in unusual config), passes with it

-------------

Commit messages:
 - Backport 61d0db3838932d4030b05ffb04ee2b0215ea686e

Changes: https://git.openjdk.org/jdk21u-dev/pull/214/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=214&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318468
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/214.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/214/head:pull/214

PR: https://git.openjdk.org/jdk21u-dev/pull/214