RFR: 8309602: update JVMTI history table for jdk 21 [v3]

[Serguei Spitsyn]

> This is a minor update of the `jvmti.xml` file.
> The JVM TI history table needs to be updated to list:
>  - Virtual threads finalized to be a permanent feature.
>  - Agent start-up in the live phase now specified to print a warning.
> 
> The JVM TI history table is maintained for convenience only and does not require a CSR.

Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:

  review: minor history table tweak

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14352/files
  - new: https://git.openjdk.org/jdk/pull/14352/files/a9e4f8eb..11db4f4f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14352&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14352&range=01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/14352.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14352/head:pull/14352

PR: https://git.openjdk.org/jdk/pull/14352