RFR: 8254105: allow static nested declarations [v3]

[Vicente Romero]

> Please review the fix for [JDK-8254105](https://bugs.openjdk.java.net/browse/JDK-8254105). The intention of the fix is to allow static members to be declared inside inner classes. The spec allowing this change can be seen at [Local and Nested Static Declarations](http://cr.openjdk.java.net/~gbierman/8246771/8246771-20200928/specs/local-statics-jls.html). This change is part of the [Records JEP](https://openjdk.java.net/jeps/395). The idea is to allow not only records to be defined inside inner classes but also interfaces, enums, static classes and methods.
> 
> TIA,
> Vicente
> 
> PS: the records spec can be accessed here [Record Classes](http://cr.openjdk.java.net/~gbierman/8246771/8246771-20200928/specs/records-jls.html). This patch also adds a test to check the changes in the Records spec to Chapter 13 "Binary Compatibility". I'm OK moving that test to a separate PR.

Vicente Romero has updated the pull request incrementally with one additional commit since the last revision:

  test cleanup

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/571/files
  - new: https://git.openjdk.java.net/jdk/pull/571/files/a118ff5e..431500d2

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=571&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=571&range=01-02

  Stats: 738 lines in 1 file changed: 291 ins; 285 del; 162 mod
  Patch: https://git.openjdk.java.net/jdk/pull/571.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/571/head:pull/571

PR: https://git.openjdk.java.net/jdk/pull/571