RFR: 8303018: Unicode Emoji Properties [v2]

[Naoto Sato]

> Proposing accessor methods to Emoji properties defined in [Unicode Technical Standard #51](https://unicode.org/reports/tr51/) in `java.lang.Character` class. This is per a request from the client group, as well as refining the currently existing ad-hoc emoji implementation in regex. A CSR has also been drafted, and I would appreciate reviews for it too.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Fixed method descriptions

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13006/files
  - new: https://git.openjdk.org/jdk/pull/13006/files/4b2a2418..0b7b7296

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13006&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13006&range=00-01

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13006.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/13006/head:pull/13006

PR: https://git.openjdk.org/jdk/pull/13006