RFR: 8282200: ShouldNotReachHere() reached by AsyncGetCallTrace after JDK-8280422 [v4]

[Johannes Bechberger]

> Fixes the mentioned bug by replacing the check in AsyncGetCallTrace using the newly introduced method `JavaThread::thread_from_jni_environment`.

Johannes Bechberger has updated the pull request incrementally with one additional commit since the last revision:

  Remove old code

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7559/files
  - new: https://git.openjdk.java.net/jdk/pull/7559/files/ca295d34..b5bd5f6e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7559&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7559&range=02-03

  Stats: 16 lines in 1 file changed: 0 ins; 16 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7559.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7559/head:pull/7559

PR: https://git.openjdk.java.net/jdk/pull/7559