RFR: 8365192: post_meth_exit should be in vm state when calling get_jvmti_thread_state [v5]

[Leonid Mesnik]

> The method
> get_jvmti_thread_state()
> should be called only while thread is in vm state.
> 
> The post_method_exit is doing some preparation before switching to vm state. This cause issues if thread is needed to initialize jvmti thread state.
> 
> The fix was found using jvmti stress agent and thus no additional regression test is required.

Leonid Mesnik 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 nine additional commits since the last revision:

 - The oop preservation and exception handling has been fixed.
 - Test added.
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8365192
 - Merge branch 'master' of https://github.com/openjdk/jdk into 8365192
 - added _
 - wong phase
 - fixed name
 - simplified after feedback
 - 8365192: post_meth_exit should be in vm state when calling get_jvmti_thread_state

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26713/files
  - new: https://git.openjdk.org/jdk/pull/26713/files/255c0ba8..d9d21af6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26713&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26713&range=03-04

  Stats: 14918 lines in 409 files changed: 8347 ins; 4914 del; 1657 mod
  Patch: https://git.openjdk.org/jdk/pull/26713.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26713/head:pull/26713

PR: https://git.openjdk.org/jdk/pull/26713