j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/annotations/annotationInterface1.kt

@@ -0,0 +1,9 @@
+import java.lang.annotation.ElementType
+import java.lang.annotation.Target
+
+annotation class Anon(public val stringArray: Array<String>, public val intArray: IntArray, // string
+                      public val string: String)
+
+Anon(string = "a", stringArray = array("a", "b"), intArray = intArray(1, 2))
+Target(ElementType.CONSTRUCTOR, ElementType.FIELD)
+annotation class I