RFR: 8300295: [AIX] TestDaemonDestroy fails due to !is_primordial_thread assertion [v6]

[Varada M]

> The assertion failure with exit value 134 for the test TestDaemonDestroy.java is because when the JNI_CreateJavaVM is being called by main thread on AIX it prevents the jvm creation on the primordial thread on AIX. This is solved in such a way that when JNI_CreateJavaVM is called it runs in pthread thus enabling the creation of jvm. 
> 
> JBS issue for this test : [JDK-8300295](https://bugs.openjdk.org/browse/JDK-8300295)

Varada M has updated the pull request incrementally with one additional commit since the last revision:

  Removed the fuctions pthread_attr_setdetachstate and pthread_attr_setguardsize

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12006/files
  - new: https://git.openjdk.org/jdk/pull/12006/files/572015e5..45b39d12

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12006&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12006&range=04-05

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/12006.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12006/head:pull/12006

PR: https://git.openjdk.org/jdk/pull/12006