Add compile_from_dill test

pkg/compiler/lib/src/world.dart

Index: pkg/compiler/lib/src/world.dart
diff --git a/pkg/compiler/lib/src/world.dart b/pkg/compiler/lib/src/world.dart
index 21088007e8b24d13c4d1a3d6a513babfe93b5746..5d3264d828cebce51e3848cb6b864247fbe63a5f 100644
--- a/pkg/compiler/lib/src/world.dart
+++ b/pkg/compiler/lib/src/world.dart
@@ -1122,13 +1122,16 @@ abstract class ClosedWorldBase implements ClosedWorld, ClosedWorldRefiner {
 
   // TODO(johnniwinther): Support [cls] as a [ClassEntity].

[Siggi Cherem (dart-lang), 2017/05/30 22:34:42]

nit: move the TODO to the `if` below

[Johnni Winther, 2017/05/31 09:08:40]

Done.

   @override
-  String dump([ClassElement cls]) {
+  String dump([ClassEntity cls]) {
     StringBuffer sb = new StringBuffer();
     if (cls != null) {
       sb.write("Classes in the closed world related to $cls:\n");
     } else {
       sb.write("Instantiated classes in the closed world:\n");
     }
+    if (cls is! ClassElement) {

[Siggi Cherem (dart-lang), 2017/05/30 22:34:43]

should we just do this upfront instead?

[Johnni Winther, 2017/05/31 09:08:40]

Done.

+      cls = null;
+    }
     getClassHierarchyNode(commonElements.objectClass)
         .printOn(sb, ' ', instantiatedOnly: cls == null, withRespectTo: cls);
     return sb.toString();