[jdk8u-dev] RFR: 8339644: Improve parsing of Day/Month in tzdata rules

[Dmitry Cherepanov]

The backport is a prerequisite for timezone data update to 2024b. Targeting the PR to jdk8u-dev repo (April release).

The changes are the same as the changes proposed in https://github.com/openjdk/jdk8u/pull/64 but now targeted to https://github.com/openjdk/jdk8u-dev

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Commit messages:
 - Backport 86a2f9c7dcb6585cabf03c0940511d11560e85b7

Changes: https://git.openjdk.org/jdk8u-dev/pull/615/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=615&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339644
  Stats: 88 lines in 3 files changed: 32 ins; 28 del; 28 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/615.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/615/head:pull/615

PR: https://git.openjdk.org/jdk8u-dev/pull/615