Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/reflection/enclosing/localClassInTopLevelFunction.kt

@@ -0,0 +1,11 @@
+// WITH_REFLECT
+// KT-4234
+
+fun box(): String {
+    class C
+
+    val name = C::class.java.getSimpleName()
+    if (name != "box\$C") return "Fail: $name"
+
+    return "OK"
+}