RFR: 8253694: Remove Thread::muxAcquire() from ThreadCrashProtection() [v3]

[Patricio Chilano Mateo]

> Hi all,
> 
> Please review the following patch. Current ThreadCrashProtection() implementation uses static members which requires
> the use of Thread::muxAcquire() to allow only one user at a time. We can avoid this synchronization requirement if each
> thread has its own ThreadCrashProtection *data. I tested it builds on Linux, macOS and Windows. Since the
> JfrThreadSampler is the only one using this I run all the tests from test/jdk/jdk/jfr/. I also run some tests with JFR
> enabled while forcing a crash in OSThreadSampler::protected_task() and tests passed with several "Thread method sampler
> crashed" UL output. Also run tiers1-3.  Thanks, Patricio

Patricio Chilano Mateo has updated the pull request incrementally with one additional commit since the last revision:

  Address Dan's comments

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/376/files
  - new: https://git.openjdk.java.net/jdk/pull/376/files/00539d6f..b93e94b8

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=376&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=376&range=01-02

  Stats: 4 lines in 2 files changed: 2 ins; 2 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/376.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/376/head:pull/376

PR: https://git.openjdk.java.net/jdk/pull/376