RFR: 8297201: Obsolete AliasLevel flag [v2]

[Tobias Hartmann]

> The AliasLevel flag was deprecated in JDK 19 by [JDK-8075816](https://bugs.openjdk.org/browse/JDK-8075816) and should now be obsoleted. Patch is slightly adjusted https://github.com/openjdk/jdk/pull/8140/commits/6a1bed2d7ed5494b051fae09d28787fd01de9635, originally from @tobiasholenstein.
> 
> Thanks,
> Tobias

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

  Removed checks from flatten_alias_type method

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11207/files
  - new: https://git.openjdk.org/jdk/pull/11207/files/7bb62ef6..68719301

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11207&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11207&range=00-01

  Stats: 8 lines in 1 file changed: 1 ins; 5 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11207.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11207/head:pull/11207

PR: https://git.openjdk.org/jdk/pull/11207