[sealed-types] RFR: Merge master

[J.Duke]

Hi all,

this is an _automatically_ generated pull request to notify you that there are 86 commits from the branch `master`that
can **not** be merged into the branch `sealed-types`:

The following files contains merge conflicts:

- make/data/jdwp/jdwp.spec
- src/java.instrument/share/classes/java/lang/instrument/Instrumentation.java
- src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/markup/HtmlStyle.java
- src/jdk.jdi/share/classes/com/sun/jdi/VirtualMachine.java

All Committers in this [project](https://openjdk.java.net/census#Optional[amber]) have access to my [personal
fork](https://github.com/openjdk-bot/amber) and can therefore help resolve these merge conflicts (you may want to
coordinate who should do this). The following paragraphs will give an example on how to solve these merge conflicts and
push the resulting merge commit to this pull request. The below commands should be run in a local clone of your
[personal fork](https://wiki.openjdk.java.net/display/skara#Skara-Personalforks) of the
[openjdk/amber](https://github.com/openjdk/amber) repository.

# Ensure target branch is up to date
$ git checkout sealed-types
$ git pull https://github.com/openjdk/amber sealed-types

# Fetch and checkout the branch for this pull request
$ git fetch https://github.com/openjdk-bot/amber +42:openjdk-bot-42
$ git checkout openjdk-bot-42

# Merge the target branch
$ git merge sealed-types

When you have resolved the conflicts resulting from the `git merge` command above, run the following commands to create
a merge commit:

$ git add paths/to/files/with/conflicts
$ git commit -m 'Merge master'


When you have created the merge commit, run the following command to push the merge commit to this pull request:

$ git push https://github.com/openjdk-bot/amber openjdk-bot-42:42

_Note_: if you are using SSH to push commits to GitHub, then change the URL in the above `git push` command accordingly.

Thanks,
J. Duke

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

Commit messages:
 - Added tag jdk-15+25 for changeset 90b266a84c06
 - 8244703: "platform encoding not initialized" exceptions with debugger, JNI
 - 8245505: Prelink j.l.ref.Reference when loading AOT library
 - 8245478: Implementation: JEP 379: Shenandoah: A Low-Pause-Time Garbage Collector (Production)
 - 8245942: Shenandoah: x86_32 builds fail after JDK-8245594
 - 8246023: Obsolete LIRFillDelaySlot
 - 8245718: Epsilon: improve configuration logging
 - 8245864: Obsolete BranchOnRegister
 - 8245955: Shenandoah: Remove LRB/is_redundant optimization
 - 8244504: C2: refactor counted loop code in preparation for long counted loop
 - ... and 76 more: https://git.openjdk.java.net/amber/compare/ea38873d...6df2a95d

The webrev contains the conflicts with sealed-types:
 - merge conflicts: https://webrevs.openjdk.java.net/amber/22/webrev.00.conflicts

Changes: https://git.openjdk.java.net/amber/pull/22/files
  Stats: 94045 lines in 496 files changed: 26316 ins; 65803 del; 1926 mod
  Patch: https://git.openjdk.java.net/amber/pull/22.diff
  Fetch: git fetch https://git.openjdk.java.net/amber pull/22/head:pull/22

PR: https://git.openjdk.java.net/amber/pull/22