Test failure of WSProviderTestCaseForked on JDK11+Windows

We are seeing failing test org.jboss.test.ws.jaxws.smoke.tools.WSProviderTestCaseForked#testOutputDirectory
https://github.com/jbossws/jbossws-cxf/blob/jbossws-cxf-5.2.4.Final/modules/testsuite/shared-tests/src/test/java/org/jboss/test/ws/jaxws/smoke/tools/WSProviderTestCaseForked.java

The error message is:

java.lang.reflect.InvocationTargetException
	at org.jboss.test.ws.jaxws.smoke.tools.WSProviderTestCaseForked.testOutputDirectory(WSProviderTestCaseForked.java:105)
Caused by: java.lang.ClassNotFoundException: org.jboss.test.ws.jaxws.smoke.tools.jaxws.AddResponse
	at org.jboss.test.ws.jaxws.smoke.tools.WSProviderTestCaseForked.testOutputDirectory(WSProviderTestCaseForked.java:105)

During the test this is called https://github.com/jbossws/jbossws-cxf/blob/jbossws-cxf-5.2.4.Final/modules/client/src/main/java/org/jboss/wsf/stack/cxf/tools/CXFProviderImpl.java#L201-L211 after which "target/wsprovide/java/org/jboss/test/ws/jaxws/smoke/tools/jaxws/" should contain both *.java and *.class files but it does not on Win+JDK11. The cause of the test error message is then the fact there are no *.class files in tested directory.

In case of JDK11 the Jdk9PlusJBossModulesAwareCompiler is used which then calls JDK internal compiler task https://github.com/jbossws/jbossws-cxf/blob/jbossws-cxf-5.2.4.Final/modules/client/src/main/java/org/jboss/wsf/stack/cxf/tools/Jdk9PlusJBossModulesAwareCompiler.java#L79-L81 which should create these files.

When I was trying to debug it on both Win and RHEL with JDK11 and compare results, there seems to be no relevant difference at what parameters are passed to methods up to this point.