RFR: 8308753: Class-File API transition to Preview [v23]

[Adam Sotona]

> Classfile API is an internal library under package `jdk.internal.classfile` in JDK 21.
> This pull request turns the Classfile API into a preview feature and moves it into `java.lang.classfile`.
> It repackages all uses across JDK and tests and adds lots of missing Javadoc.
> 
> This PR goes in sync with [JDK-8308754](https://bugs.openjdk.org/browse/JDK-8308754): Class-File API (Preview) (CSR)
> and [JDK-8280389](https://bugs.openjdk.org/browse/JDK-8280389): Class-File API (Preview) (JEP).
> 
> Online javadoc is available at: 
> https://cr.openjdk.org/~asotona/JDK-8308753-preview/api/java.base/java/lang/classfile/package-summary.html
> 
> In addition to the primary transition to preview, this pull request also includes:
> - All Classfile* classes ranamed to ClassFile* (based on JEP discussion).
> - A new preview feature, `CLASSFILE_API`, has been added.
> - Buildsystem tool required a little patch to support annotated modules.
> - All JDK modules using the Classfile API are newly participating in the preview.
> - All tests that use the Classfile API now have preview enabled.
> - A few Javac tests not allowing preview have been partially reverted; their conversion can be re-applied when the Classfile API leaves preview mode.
> 
> Despite the number of affected files, this pull request is relatively straight-forward. The preview version of the Classfile API is based on the internal version of the library from the JDK master branch, and there are no API features added.
> 
> Please review this pull request to help the Classfile API turn into a preview.
> 
> Any comments are welcome.
> 
> Thanks,
> Adam

Adam Sotona has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 357 commits:

 - fixed jdk.jfr
 - Merge branch 'master' into JDK-8308753-preview
   
   # Conflicts:
   #	src/java.base/share/classes/module-info.java
 - applied javadoc fix suggestions
 - fixed new benchmark
 - Merge branch 'master' into JDK-8308753-preview
   
   # Conflicts:
   #	src/java.base/share/classes/jdk/internal/classfile/impl/AbstractPoolEntry.java
 - removed trailing space
 - Merge branch 'master' into JDK-8308753-preview
   
   # Conflicts:
   #	src/java.base/share/classes/module-info.java
 - package info javadoc improvements
 - removed obsolete exports from BuildMicrobenchmark.gmk
 - Merge branch 'master' into JDK-8308753-preview
 - ... and 347 more: https://git.openjdk.org/jdk/compare/9e98ee67...0587f208

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Changes: https://git.openjdk.org/jdk/pull/15706/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15706&range=22
  Stats: 32165 lines in 768 files changed: 14622 ins; 14054 del; 3489 mod
  Patch: https://git.openjdk.org/jdk/pull/15706.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15706/head:pull/15706

PR: https://git.openjdk.org/jdk/pull/15706