RFR: 8262889: Compiler implementation for Record Patterns [v7]

[Jan Lahoda]

> 8262889: Compiler implementation for Record Patterns
> 
> A first version of a patch that introduces record patterns into javac as a preview feature. For the specification, please see:
> http://cr.openjdk.java.net/~gbierman/jep427+405/jep427+405-20220426/specs/patterns-switch-record-patterns-jls.html
> 
> There are two notable tricky parts:
> -in the parser, it was necessary to improve the `analyzePattern` method to handle nested/record patterns, while still keeping error recovery reasonable
> -in the `TransPatterns`, the desugaring of the record patterns is very straightforward - effectivelly the record patterns are desugared into guards/conditions. This will likely be improved in some future version/preview
> 
> `MatchException` has been extended to cover additional cases related to record patterns.

Jan Lahoda has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 34 commits:

 - Merge branch 'master' into patterns-record-deconstruction3
 - Post merge fix.
 - Merge branch 'master' into patterns-record-deconstruction3
 - Fixing (non-)exhaustiveness for enum.
 - Merge branch 'type-pattern-third' into patterns-record-deconstruction3
 - Merge branch 'master' into type-patterns-third
 - Using Type.isRaw instead of checking the AST structure.
 - Exhaustiveness should accept supertypes of the specified type.
 - Renaming the features from deconstruction pattern to record pattern.
 - Fixing guards after record patterns.
 - ... and 24 more: https://git.openjdk.java.net/jdk/compare/742644e2...f49d3f0a

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

Changes: https://git.openjdk.java.net/jdk/pull/8516/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8516&range=06
  Stats: 2255 lines in 50 files changed: 2169 ins; 15 del; 71 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8516.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8516/head:pull/8516

PR: https://git.openjdk.java.net/jdk/pull/8516