It seems IBM JDK has an issue with using clone() method for arrays in static method of interface. Using arrays clone() method causes following exception for IBM JDK:

java.lang.IllegalAccessError: Class org/wildfly/security/password/interfaces/SaltedSimpleDigestPassword illegally accessing "protected" member of class [B
        at org.wildfly.security.password.interfaces.SaltedSimpleDigestPassword.createRaw(SaltedSimpleDigestPassword.java:112)
    ...

Issue affects only direct usage of arrays clone() method from static method of interface.
Example, calling methodWillFail() will fail with IBM JDK:

public interface SimpleInterface {
    static int[] methodWillFail() {
        int[] array = {1, 2};
        return array.clone();
    }
}

Workaround is simple. Calling static method of another class using arrays clone() works for IBM JDK 8.
Example, calling methodWillNotFail() will pass with IBM JDK:

public interface SimpleInterface {
    static int[] methodWillNotFail() {
        return SimpleClass.methodOk();
    }
}

public class SimpleClass {
    static int[] methodOk() {
        int[] array = {1, 2};
        return array.clone();
    }
}

Affected interfaces:
org.wildfly.security.auth.server.NameRewriter.java
org.wildfly.security.authz.RoleMapper.java
org.wildfly.security.password.interfaces.SaltedSimpleDigestPassword.java
org.wildfly.security.password.interfaces.OneTimePassword.java
org.wildfly.security.password.interfaces.BSDUnixDESCryptPassword.java
org.wildfly.security.password.interfaces.BCryptPassword.java
org.wildfly.security.password.interfaces.SimpleDigestPassword.java
org.wildfly.security.password.interfaces.DigestPassword.java
org.wildfly.security.password.interfaces.ScramDigestPassword.java
org.wildfly.security.ssl.SNIServerSSLContextSelector.java

This issue causes errors in following test cases running with IBM JDK:
org.wildfly.security.auth.KeyStoreBackedSecurityRealmTest
org.wildfly.security.auth.realm.jdbc.PasswordSupportTest
org.wildfly.security.password.impl.BCryptPasswordTest
org.wildfly.security.auth.realm.ldap.UserPasswordPasswordUtilTest
org.wildfly.security.ldap.PasswordSupportSuiteChild
org.wildfly.security.password.impl.BSDUnixDESCryptTest