Pull ant-launcher.jar into the classpath as well

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@275529 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/junit/JUnitTask.java

@@ -618,6 +618,7 @@ public class JUnitTask extends Task {
     public void init() {
         antRuntimeClasses = new Path(getProject());
         addClasspathEntry("/junit/framework/TestCase.class");
+        addClasspathEntry("/org/apache/tools/ant/launch/AntMain.class");
         addClasspathEntry("/org/apache/tools/ant/Task.class");
         addClasspathEntry("/org/apache/tools/ant/taskdefs/optional/junit/JUnitTestRunner.class");
     }