Move blackBoxFile() testData to box/ directory

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

compiler/testData/codegen/box/localClasses/enum.kt

@@ -0,0 +1,8 @@
+fun box(): String {
+    enum class K {
+        O
+        K
+    }
+
+    return K.O.toString() + K.K.toString()
+}

compiler/testData/codegen/box/localClasses/noclosure.kt

@@ -0,0 +1,11 @@
+fun box(): String {
+    open class K {
+        val o = "O"
+    }
+
+    class Bar : K() {
+        val k = "K"
+    }
+
+    return K().o + Bar().k
+}

compiler/testData/codegen/box/localClasses/object.kt

@@ -0,0 +1,7 @@
+fun box(): String {
+    object K {
+        val ok = "OK"
+    }
+
+    return K.ok
+}

compiler/testData/codegen/box/localClasses/withclosure.kt

@@ -0,0 +1,8 @@
+fun box(): String {
+    val x = "OK"
+    class Aaa {
+        val y = x
+    }
+
+    return Aaa().y
+}