[jdk17u-dev] RFR: 8262721: Add Tests to verify single iteration loops are properly optimized

[Goetz Lindenmaier]

I backport this for parity with 17.0.6-oracle.

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Commit messages:
 - Backport 69e390a0e86f82eaa7bcdbc3ef509734dbe3b22f

Changes: https://git.openjdk.org/jdk17u-dev/pull/693/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=693&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8262721
  Stats: 139 lines in 1 file changed: 139 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/693.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/693/head:pull/693

PR: https://git.openjdk.org/jdk17u-dev/pull/693