On AIX using zlibNX may cause ClassNotFoundException

[pshipton]

Experienced the following problem on AIX 7.3 P10, which is configured to support zlibNX, and Semeru will use it be default. Disable using -XX:-UseZlibNX and it no longer occurs.

00:52:14  /home/jenkins/workspace/Test_openjdk23_j9_sanity.jck_ppc64_aix/jdkbinary/j2sdk-image/bin/java -cp ./bin/TestKitGen.jar org.openj9.envInfo.EnvDetector
00:52:14  Exception in thread "main" java.lang.NoClassDefFoundError: org.openj9.envInfo.MachineInfo
00:52:14  	at org.openj9.envInfo.EnvDetector.parseArgs(EnvDetector.java:32)
00:52:14  	at org.openj9.envInfo.EnvDetector.main(EnvDetector.java:28)
00:52:14  Caused by: java.lang.ClassNotFoundException: org.openj9.envInfo.MachineInfo
00:52:14  	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:827)
00:52:14  	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
00:52:14  	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:1099)
00:52:14  	... 2 more

Trying to look at the class with javap you get unexpected end of file while reading org.openj9.envInfo.MachineInfo.

jdk11, 17 seem fine, this particular problem only occurs with jdk21, 23. However we don't know how the bug might affect earlier versions.