Move blackBoxFile() testData to box/ directory

Delete all test methods (and empty test classes), since they'll be
auto-generated

compiler/testData/codegen/box/objects/objectLiteralInClosure.kt

@@ -0,0 +1,17 @@
+package p
+
+class C(val y : Int) {
+  val initChild = { ->
+    object : java.lang.Object() {
+      override fun toString(): String {
+          return "child" + y
+      }
+    }
+  }
+}
+
+fun box(): String {
+  val c = C(3).initChild
+  val x = c().toString()
+  return if(x == "child3") "OK" else x
+}