RFR: JDK-8075816: Deprecate AliasLevel flag since it is broken [v3]

[Tobias Holenstein]

> Deprecate the `AliasLevel` flag. `AliasLevel` can have the following values:  
> 
> "0 - for no aliasing, "
> "1 - for oop/field/static/array split, "
> "2 - for class split, "
> "3 - for unique instances"
> 
>  - Deprecate AliasLevel in JDK 19.
>  - Obsolete it in JDK 20
>  - Expire it in JDK 21.
> 
> Users will now get the following message when running:
> `java -XX:AliasLevel= Java HotSpot(TM) 64-Bit Server VM warning: Option AliasLevel was deprecated in version 19.0 and will likely be removed in a future release.`

Tobias Holenstein has updated the pull request incrementally with one additional commit since the last revision:

  Revert "Obsolete AliasLevel flag"
  
  This reverts commit 6a1bed2d7ed5494b051fae09d28787fd01de9635.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8140/files
  - new: https://git.openjdk.java.net/jdk/pull/8140/files/6a1bed2d..782fb37d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8140&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8140&range=01-02

  Stats: 77 lines in 12 files changed: 57 ins; 2 del; 18 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8140.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8140/head:pull/8140

PR: https://git.openjdk.java.net/jdk/pull/8140