[jdk21u-dev] RFR: 8340552: Harden TzdbZoneRulesCompiler against missing zone names

[Antonio Vieiro]

Clean backport of [JDK-8340552](https://bugs.openjdk.org/browse/JDK-8340552).

Tested tier1 tests and processing data [from tzdata/2024b.](https://data.iana.org/time-zones/releases/tzdb-2024b.tar.lz)

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Commit messages:
 - Backport 1bc13a1c10a580f84f1b7686c95344ec2633f611

Changes: https://git.openjdk.org/jdk21u-dev/pull/1180/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1180&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340552
  Stats: 12 lines in 1 file changed: 8 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1180.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1180/head:pull/1180

PR: https://git.openjdk.org/jdk21u-dev/pull/1180