RFR: 8328649: Disallow enclosing instances for local classes in constructor prologues [v2]

[Archie Cobbs]

> A local class declared in a static context is not supposed to have an immediately enclosing instance (§15.9.2). That includes local classes declared in constructors prior to `super()` (during the "constructor prologue" in the new lingo).
> 
> However, the compiler is allowing code like this to successfully compile:
> 
> import java.util.concurrent.atomic.*;
> public class Test extends AtomicReference<Object> {
>   
>     public Test() {
>         super(switch (0) {
>           default -> {
>               class Local { { Test.this.hashCode(); } }   // this should fail
>               yield null;
>             }
>         });
>     }
> }
> 
> This patch fixes the "leak".

Archie Cobbs has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'master' into JDK-8328649
 - Remove obsolete test cases.
 - No enclosing instance for local classes in constructor prologues.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18416/files
  - new: https://git.openjdk.org/jdk/pull/18416/files/d98cb3d5..c9d399d7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18416&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18416&range=00-01

  Stats: 357608 lines in 2856 files changed: 17713 ins; 14957 del; 324938 mod
  Patch: https://git.openjdk.org/jdk/pull/18416.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18416/head:pull/18416

PR: https://git.openjdk.org/jdk/pull/18416