j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/ifStatement/elseIf.java

@@ -0,0 +1,16 @@
+//method
+void foo() {
+  if (a)
+    System.out.println("a")
+  else if (b)
+    System.out.println("b")
+  else
+    System.out.println("else")
+
+  if (c) {
+    System.out.println("c")
+  }
+  else if (d) {
+    System.out.println("d")
+  }
+}