Don't consider a directory to be a package if there's a .java or .class file with the same name in its parent directory

#KT-12664 Fixed

compiler/tests-common/org/jetbrains/kotlin/test/MockLibraryUtil.java

@@ -155,7 +155,7 @@ public class MockLibraryUtil {
         }
     }
 
-    private static File createJarFile(File contentDir, File dirToAdd, String sourcesPath, String jarName, boolean addSources) throws IOException {
+    public static File createJarFile(File contentDir, File dirToAdd, String sourcesPath, String jarName, boolean addSources) throws IOException {
         File jarFile = new File(contentDir, jarName + ".jar");
 
         ZipOutputStream zip = new ZipOutputStream(new FileOutputStream(jarFile));