RFR: 8303374: Implement JEP 455: Primitive Types in Patterns, instanceof, and switch (Preview) [v44]

[Aggelos Biboudis]

> This is the proposed patch for Primitive types in patterns, instanceof, and switch (Preview).
> 
> Draft spec here: https://cr.openjdk.org/~abimpoudis/instanceof/latest/

Aggelos Biboudis has updated the pull request incrementally with two additional commits since the last revision:

 - Enhance Javadoc of ExactConversionsSupport (2)
 - Enhance Javadoc of ExactConversionsSupport

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15638/files
  - new: https://git.openjdk.org/jdk/pull/15638/files/9b7fb7fc..aa9b2fcd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15638&range=43
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15638&range=42-43

  Stats: 33 lines in 1 file changed: 15 ins; 3 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/15638.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15638/head:pull/15638

PR: https://git.openjdk.org/jdk/pull/15638