RFR: 8339644: Improve parsing of Day/Month in tzdata rules [v2]

[Naoto Sato]

> Fixing TZDB build tool to accommodate full month/day names. Recently released tzdb2024b included (inadvertently) full month name "April", which is allowed by the spec (zic.8), but never used. This will cause build failure of the JDK. The proposed fix is manually tested by modifying the tzdb files to include full month names, and confirmed the successful build of the JDK.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Fixing failing test

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20893/files
  - new: https://git.openjdk.org/jdk/pull/20893/files/22419a93..8e711667

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20893&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20893&range=00-01

  Stats: 8 lines in 2 files changed: 6 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/20893.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20893/head:pull/20893

PR: https://git.openjdk.org/jdk/pull/20893