It seems like the fix in JDK-8373875 did not fix it entirely.
This happens under several flag constellations:
- -XX:+UnlockDiagnosticVMOptions -XX:+AOTStreamableObjects -XX:+UseZGC --enable-preview
- -XX:+UseZGC --enable-preview
- -XX:-UseCompressedOops --enable-preview

java.lang.RuntimeException: 'Unknown diagnostic command' missing from stdout/stderr
at jdk.test.lib.process.OutputAnalyzer.shouldContain(OutputAnalyzer.java:253)
at DumpSymbolAndStringTable.main(DumpSymbolAndStringTable.java:70)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:565)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1516)

JavaTest Message: Test threw exception: java.lang.RuntimeException: 'Unknown diagnostic command' missing from stdout/stderr
JavaTest Message: shutting down test