Missing dependency for ibm jdk8 after descope ecj

Following tests from human-task-core are failing in ibm jdk8 after introducing DROOLS-5780:

• org.jbpm.services.task.LifeCycleLocalWithRuleServiceTest
• org.jbpm.services.task.assignment.BusinessRuleAssignmentTest

[ERROR] testCompleteTaskWithCheckByRule(org.jbpm.services.task.LifeCycleLocalWithRuleServiceTest) Time elapsed: 2.798 s <<< FAILURE!
java.lang.AssertionError: Task should not be created due to rule violation
at org.junit.Assert.fail(Assert.java:89)

[ERROR] testAssignmentAssignToBobbaFetBasedOnDataInput(org.jbpm.services.task.assignment.BusinessRuleAssignmentTest) Time elapsed: 0.917 s <<< ERROR!
java.lang.RuntimeException: java.lang.NoSuchFieldException: classes
at org.drools.compiler.commons.jci.compilers.NativeJavaCompiler$MemoryFileManager.indexClassesByPackage(NativeJavaCompiler.java:401)