Move compile-time constant registrations to the backend.

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 8d24ad2ee56f12254a7bbdd91bbb20756eb26820..e489fb187294d571ad7d413a97c685b2ec130e64 100644
--- a/sdk/lib/_internal/compiler/implementation/enqueue.dart
+++ b/sdk/lib/_internal/compiler/implementation/enqueue.dart
@@ -104,7 +104,6 @@ abstract class Enqueuer {
    */
   void addToWorkList(Element element) {
     assert(invariant(element, element.isDeclaration));
-    if (element.isForeign(compiler)) return;
     internalAddToWorkList(element);
   }
 
@@ -614,7 +613,7 @@ class ResolutionEnqueuer extends Enqueuer {
     if (getCachedElements(element) != null) return;
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(element,
-                                          "Resolution work list is closed.");
+          "Resolution work list is closed. Trying to add $element.");
     }
     compiler.world.registerUsedElement(element);
 
@@ -681,11 +680,14 @@ class ResolutionEnqueuer extends Enqueuer {
    * The action is performed as part of the post-processing immediately after
    * the resolution queue has been closed. As a consequence, [action] must not
    * add elements to the resolution queue.
+   *
+   * The queue is processed in FIFO order.
    */
   void addPostProcessAction(Element element, PostProcessAction action) {
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(element,
-                                          "Resolution work list is closed.");
+          "Resolution work list is closed. "
+          "Trying to add post process action for $element");
     }
     postQueue.add(new PostProcessTask(element, action));
   }
@@ -720,13 +722,16 @@ class CodegenEnqueuer extends Enqueuer {
       member.isAbstract(compiler) || generatedCode.containsKey(member);
 
   void internalAddToWorkList(Element element) {
+    // Don't generate code for foreign elements.
+    if (element.isForeign(compiler)) return;
+
     // Codegen inlines field initializers, so it does not need to add
     // individual fields in the work list.
     if (element.isField() && element.isInstanceMember()) return;
 
     if (queueIsClosed) {
       throw new SpannableAssertionFailure(element,
-                                          "Codegen work list is closed.");
+          "Codegen work list is closed. Trying to add $element");
     }
     CodegenWorkItem workItem = new CodegenWorkItem(
         element, itemCompilationContextCreator());