[jdk11u-dev] RFR: 8283849: AsyncGetCallTrace may crash JVM on guarantee

[Jaroslav Bachorik]

A fairly straightforward backport.

There are only two types of minor adjustments that had to be done:
- line number adjustments due to the difference in `thread.cpp/hpp` files
- missing `Thread->as_java_thread()` function - can be exactly replicated by `((JavaThread*)current_thread)` cast

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Commit messages:
 - Backport 19639855311a47ed532547743ea3873eb8b016d3

Changes: https://git.openjdk.org/jdk11u-dev/pull/1148/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=1148&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8283849
  Stats: 21 lines in 4 files changed: 19 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1148.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1148/head:pull/1148

PR: https://git.openjdk.org/jdk11u-dev/pull/1148