<i18n dev> RFR: JDK-8317612: ChoiceFormat and MessageFormat constructors call non-final public method [v3]

[Justin Lu]

> Please review this PR and [CSR](https://bugs.openjdk.org/browse/JDK-8317630) which makes the implications of overriding _ChoiceFormat::applyPattern_ and _MessageFormat::applyPattern_ apparent by adding a implSpec tag to the method. 
> 
> That is, the constructors of both ChoiceFormat and MessageFormat call the public and non-final applyPattern method; any changes in the applyPattern of a subclass will be reflected in the constructors as well.

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

 - additional cleanup/wording changes
 - replace spec fix with private methods

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16064/files
  - new: https://git.openjdk.org/jdk/pull/16064/files/dc9cbae6..74847121

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16064&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16064&range=01-02

  Stats: 64 lines in 2 files changed: 35 ins; 13 del; 16 mod
  Patch: https://git.openjdk.org/jdk/pull/16064.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16064/head:pull/16064

PR: https://git.openjdk.org/jdk/pull/16064