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/kt2224.kt

@@ -0,0 +1,44 @@
+trait A {
+    fun foo(): Int
+}
+
+class B1 : A {
+    override fun foo() = 10
+}
+
+class B2(val z: Int) : A {
+    override fun foo() = z
+}
+
+
+
+fun f1(b: B1): Int {
+    val o = object : A by b { }
+    return o.foo()
+}
+
+fun f2(b: B2): Int {
+    val o = object : A by B2(b.z) { }
+    return o.foo()
+}
+
+fun f3(b: B2, mult: Int): Int {
+    val o = object : A by B2(mult * b.z) { }
+    return o.foo()
+}
+
+fun f4(b: B1, x: Int, y: Int, z: Int): Int {
+    val o = object : A by b {
+        fun bar() = x + y + z
+    }
+    return o.foo()
+}
+
+
+fun box(): String {
+    if (f1(B1()) != 10) return "fail #1"
+    if (f2(B2(239)) != 239) return "fail #2"
+    if (f3(B2(239), 2) != 239*2) return "fail #3"
+    if (f4(B1(), 1, 2, 3) != 10) return "fail #4"
+    return "OK"
+}