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/kt640.kt

@@ -0,0 +1,29 @@
+package demo
+
+public open class Identifier<T>(myName : T?, myHasDollar : Boolean) {
+    private val myName : T?
+    private var myHasDollar : Boolean
+    private var myNullable : Boolean = true
+
+    {
+        $myName = myName
+        $myHasDollar = myHasDollar
+    }
+
+    open public fun getName() : T? {
+        return myName
+    }
+
+    class object {
+        open public fun init<T>(name : T?) : Identifier<T> {
+            val __ = Identifier<T>(name, false)
+            return __
+        }
+    }
+}
+
+fun box() : String {
+    var i3 : Identifier<*>? = Identifier.init<String?>("name")
+    System.out?.println("Hello, " + i3?.getName())
+    return "OK"
+}