Start tracking all registered elements in one big full function set

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js;
 
 class EnqueueTask extends CompilerTask {
   final ResolutionEnqueuer resolution;
   final CodegenEnqueuer codegen;
 
@@ skipping 102 matching lines @@
   }
 
   /**
    * Documentation wanted -- johnniwinther
    */
   void processInstantiatedClassMember(ClassElement cls, Element member) {
     assert(invariant(member, member.isDeclaration));
     if (isProcessed(member)) return;
     if (!member.isInstanceMember()) return;
     if (member.isField()) {
-      // Native fields need to go into instanceMembersByName as they are virtual
-      // instantiation points and escape points.
-      // Test the enclosing class, since the metadata has not been parsed yet.
+      // Fields are implicitly used by the constructor of the
+      // instantiated class they are part of.
+      compiler.world.registerUsedElement(member);
+      // Native fields need to go into instanceMembersByName as they
+      // are virtual instantiation points and escape points. Test the
+      // enclosing class, since the metadata has not been parsed yet.
       if (!member.enclosingElement.isNative()) return;
     }
 
     String memberName = member.name.slowToString();
 
     if (member.kind == ElementKind.FUNCTION) {
       if (member.name == Compiler.NO_SUCH_METHOD) {
         enableNoSuchMethod(member);
       }
       if (universe.hasInvocation(member, compiler)) {
@@ skipping 399 matching lines @@
     while(!queue.isEmpty) {
       // TODO(johnniwinther): Find an optimal process order for codegen.
       f(queue.removeLast());
     }
   }
 
   void _logSpecificSummary(log(message)) {
     log('Compiled ${generatedCode.length} methods.');
   }
 }