RFR: 7903240: Unable to gather JCov coverage for JCK19 vs JDK19/20

[Leonid Kuskov]

This is the fix for https://bugs.openjdk.org/browse/CODETOOLS-7903240

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Commit messages:
 - 7903240: Unable to gather JCov coverage for JCK19 vs OpenJDK19 b22, JDK 20
 - 7903240: Unable to gather JCov coverage for JCK19 vs OpenJDK19 b22, JDK 20

Changes: https://git.openjdk.org/jcov/pull/20/files
 Webrev: https://webrevs.openjdk.org/?repo=jcov&pr=20&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903240
  Stats: 500 lines in 13 files changed: 127 ins; 85 del; 288 mod
  Patch: https://git.openjdk.org/jcov/pull/20.diff
  Fetch: git fetch https://git.openjdk.org/jcov pull/20/head:pull/20

PR: https://git.openjdk.org/jcov/pull/20