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/kt1047.kt

@@ -0,0 +1,13 @@
+public open class Test() {
+    open public fun test() : Unit {
+        System.out?.println(hello)
+    }
+    class object {
+        private val hello : String? = "Hello"
+    }
+}
+
+fun box() : String {
+    Test().test()
+    return "OK"
+}