<i18n dev> RFR: JDK-8318761: MessageFormat pattern support for CompactNumberFormat, ListFormat, and DateTimeFormatter [v4]

[Justin Lu]

> Please review this PR and [CSR](https://bugs.openjdk.org/browse/JDK-8319344) which adds MessageFormat pattern support for the following subformats: ListFormat, CompactNumberFormat, and DateTimeFormatter. This change is intended to provide pattern support for the more recently added JDK Format subclasses, as well as improving java.time formatting within i18n. The draft javadoc can be viewed here: https://cr.openjdk.org/~jlu/docs/api/java.base/java/text/MessageFormat.html. Please see the CSR for more in-depth behavioral changes, as well as limitations.
> 
> The `FormatTypes`:  dtf_date, dtf_time, dtf_datetime, pre-defined DateTimeFormatter(s), and list are added.
> The `FormatStyles`: compact_short, compact_long, or, and unit are added.
> 
> For example, previously,
> 
> 
> Object[] args = {LocalDate.of(2023, 11, 16), LocalDate.of(2023, 11, 27)};
> MessageFormat.format("It was {0,date,full}, now it is {1,date,full}", args);
> 
> 
> would throw `Exception java.lang.IllegalArgumentException: Cannot format given Object as a Date`
> 
> Now, a user can call
> 
> 
> MessageFormat.format("It was {0,dtf_date,full}, now it is {1,dtf_date,full}", args);
> 
> 
> which returns "It was Thursday, November 16, 2023, now it is Friday, November 17, 2023"

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

 - Apply spacing suggestions
   
   Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>
 - add expected message to exception checking

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/17663/files
  - new: https://git.openjdk.org/jdk/pull/17663/files/bf0174ff..5ae60000

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17663&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17663&range=02-03

  Stats: 18 lines in 3 files changed: 9 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/17663.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17663/head:pull/17663

PR: https://git.openjdk.org/jdk/pull/17663