j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/newClassExpression/newAnonymousClass3.kt

@@ -0,0 +1,19 @@
+import kotlinApi.KotlinTrait
+
+class C {
+    fun foo() {
+        val t = object : KotlinTrait {
+            override fun nullableFun(): String? {
+                return null
+            }
+
+            override fun notNullableFun(): String {
+                return ""
+            }
+
+            override fun nonAbstractFun(): Int {
+                return 0
+            }
+        }
+    }
+}