Include internal library members when enqueuing everything.

sdk/lib/_internal/compiler/implementation/enqueue.dart

Index: sdk/lib/_internal/compiler/implementation/enqueue.dart
diff --git a/sdk/lib/_internal/compiler/implementation/enqueue.dart b/sdk/lib/_internal/compiler/implementation/enqueue.dart
index 1b79960c95e6318c65e1d36430a03f526a1ad78c..fabf8134dcb432456c74044e7c5bff43bded5caf 100644
--- a/sdk/lib/_internal/compiler/implementation/enqueue.dart
+++ b/sdk/lib/_internal/compiler/implementation/enqueue.dart
@@ -24,15 +24,9 @@ class EnqueueTask extends CompilerTask {
       ScopeContainerElement container = null;
       if (element.isLibrary) {
         LibraryElement library = element;
-        // Don't include private implementation libraries.  These
-        // libraries contain special classes that cause problems
-        // in other parts of the resolver (in particular Null and Void).
-        // TODO(ahe): Consider lifting this restriction.
-        if (!library.isInternalLibrary) {
-          container = library;
-          // TODO(ahe): Is this right?  Is this necessary?
-          name = library.getLibraryOrScriptName();
-        }
+        container = library;
+        // TODO(ahe): Is this right?  Is this necessary?
+        name = library.getLibraryOrScriptName();
       } else if (element.isClass) {
         ClassElement cls = element;
         cls.ensureResolved(compiler);