Please review this PR and [CSR](https://bugs.openjdk.org/browse/JDK-8314822)
which allows for the _Format_ segment of a ChoiceFormat pattern to use the
ChoiceFormat Relational symbols without the need to escape them using quotes.
Previously, using a non escaped Relational symbol within a _Format_ segment
would throw an IAE.
Implementation wise, this can be achieved by adding an additional check of
`part == 0` to the relational symbol conditional. This is safe to do, as any
subsequent relational symbols should only come after a '|' is parsed, which
sets part back to 0. This ensures that for the duration of `part = 1` (Format
segment), the relational symbols can be used without syntactic meaning.
For example, this change allows behavior such as: `new ChoiceFormat("1#The code
is #7281")`. Previously, the workaround would have been new
`ChoiceFormat("1#The code is '#'7281")` to achieve the same formatted behavior.
Please see the CSR for more detail.
Additionally, this change also includes an unrelated grouping of the
ChoiceFormat examples under a single header: **Usage Information**.
-------------
Commit messages:
- update PatternsTest
- more accurately define the SubPattern note
- init
Changes: https://git.openjdk.org/jdk/pull/17640/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17640&range=00
Issue: https://bugs.openjdk.org/browse/JDK-6285888
Stats: 210 lines in 3 files changed: 144 ins; 59 del; 7 mod
Patch: https://git.openjdk.org/jdk/pull/17640.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/17640/head:pull/17640
PR: https://git.openjdk.org/jdk/pull/17640
