RFR: 8339166: java/lang/String/concat/HiddenClassUnloading.java fails on AIX and Linux ppc64le after JDK-8336856

[Matthias Baesken]

We see HiddenClassUnloading.java failing on the ppc64 based platforms. On AIX it seems to fail always; Linux ppc64le sometimes.
Failure output :
java.lang.RuntimeException: unloadedClassCount is zero
at HiddenClassUnloading.main(HiddenClassUnloading.java:66)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:573)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1575)

Ergonomics sets on these platforms the heap to 32M 

[0.045s][info ][gc,init ] Heap Min Capacity: 32M
[0.045s][info ][gc,init ] Heap Initial Capacity: 32M
[0.045s][info ][gc,init ] Heap Max Capacity: 32M

So we need more iterations in the test to trigger the class unloading.

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Commit messages:
 - JDK-8339166

Changes: https://git.openjdk.org/jdk/pull/20771/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20771&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8339166
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/20771.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20771/head:pull/20771

PR: https://git.openjdk.org/jdk/pull/20771