<i18n dev> RFR: JDK-8314611: Provide more explicative error message parsing Currencies [v2]

[Justin Lu]

> Please review this PR which updates some exceptions in j.util.Currency to have an explicit error message (as opposed to nothing).
> 
> The exceptions are thrown when the ISO 4217/3166 currency/country codes are in an invalid form, or do not exist.

Justin Lu has updated the pull request incrementally with two additional commits since the last revision:

 - 4217->3166
 - Include the private table methods

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15458/files
  - new: https://git.openjdk.org/jdk/pull/15458/files/afa2e835..4fe94845

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15458&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15458&range=00-01

  Stats: 4 lines in 1 file changed: 2 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15458.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15458/head:pull/15458

PR: https://git.openjdk.org/jdk/pull/15458