RFR: 8307153: JVMTI GetThreadState on carrier should return STATE_WAITING [v2]

[Serguei Spitsyn]

> When a virtual thread is mounted, the carrier thread should be reported as "waiting" until the virtual thread unmounts. Right now, GetThreadState reports a state based the JavaThread status when it should return JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY.
> The fix adds:
>  - a special case for passive carrier threads
>  - necessary test coverage to the existing JVMTI test: `serviceability/jvmti/vthread/ThreadStateTest`.
> 
> Testing:
>    - tested with the updated test: `serviceability/jvmti/vthread/ThreadStateTest`
>    - submitted mach5 tiers 1-5
>    - TBD: to submit mach5 tier 6

Serguei Spitsyn 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 three additional commits since the last revision:

 - Merge
 - minor tweaks in libThreadStateTest.cpp
 - 8307153: JVMTI GetThreadState on carrier should return STATE_WAITING

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14298/files
  - new: https://git.openjdk.org/jdk/pull/14298/files/84d8825f..e60da02e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14298&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14298&range=00-01

  Stats: 10489 lines in 228 files changed: 8499 ins; 1035 del; 955 mod
  Patch: https://git.openjdk.org/jdk/pull/14298.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14298/head:pull/14298

PR: https://git.openjdk.org/jdk/pull/14298