j2k: flatten test cases and testData directory structure

Move j2k/test/tests -> j2k/tests, j2k/test/testData -> j2k/testData

j2k/testData/fileOrElement/equals/Equals1.java

@@ -0,0 +1,12 @@
+interface I {
+}
+
+class C{
+    boolean foo1(I i1, I i2) {
+        return i1.equals(i2)
+    }
+
+    boolean foo2(I i1, I i2) {
+        return !i1.equals(i2)
+    }
+}