RFR: 8328874: Class::forName0 should validate the class name length early [v6]

[Guanqiang Han]

> Validate class name length immediately after GetStringUTFLength() in Class.forName0. This prevents potential issues caused by overly long class names before they reach later code that would reject them, throwing ClassNotFoundException early.

Guanqiang Han has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains eight additional commits since the last revision:

 - add regression test
 - Merge remote-tracking branch 'upstream/master' into 8328874
 - Update Class.java
   
   updates the class name length validation logic on the Java side
 - Update Class.java
   
   correct length of class name
 - Update Class.java
   
   fix whitespace errors
 - move check into java side
 - Merge remote-tracking branch 'upstream/master' into 8328874
 - 8328874: Class::forName0 should validate the class name length early
   
   Validate class name length immediately after GetStringUTFLength() in Class.forName0. This prevents potential issues caused by overly long class names before they reach later code that would reject them, throwing ClassNotFoundException early.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26802/files
  - new: https://git.openjdk.org/jdk/pull/26802/files/27971bf3..9ed4248d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26802&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26802&range=04-05

  Stats: 7782 lines in 348 files changed: 3681 ins; 2841 del; 1260 mod
  Patch: https://git.openjdk.org/jdk/pull/26802.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26802/head:pull/26802

PR: https://git.openjdk.org/jdk/pull/26802