Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/superExpression/classAdotSuperFoo.java

@@ -0,0 +1,12 @@
+//file
+class Base {
+  void foo();
+}
+
+class A extends Base {
+  class C {
+    void test() {
+      A.super.foo();
+    }
+  }
+}