Move blackBoxFile() testData to box/ directory

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

compiler/testData/codegen/box/classes/privateOuterProperty.kt

@@ -0,0 +1,27 @@
+class C{
+    private var v : Int = 0
+
+    public fun foo() : Int {
+        {
+            v = v + 1
+        }.invoke()
+
+        object : Runnable {
+            public override fun run() {
+                v = v + 1
+            }
+        }.run()
+
+        Inner().innerFun()
+
+        return v
+    }
+
+    private inner class Inner() {
+        fun innerFun() {
+            v = v + 1
+        }
+    }
+}
+
+fun box() = if (C().foo() == 3) "OK" else "NOT OK"