Avoid creating ConstructedConstantExpression for deferred constant.

pkg/compiler/lib/src/resolution/members.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.
 
 library dart2js.resolution.members;
 
 import '../common/names.dart' show
     Selectors;
 import '../compiler.dart' show
     Compiler;
@@ skipping 3875 matching lines @@
               node.newToken, MessageKind.NON_CONST_BLOAT,
               {'name': compiler.symbolClass.name});
         }
         registry.registerNewSymbol();
       }
     } else if (isMirrorsUsedConstant) {
       compiler.mirrorUsageAnalyzerTask.validate(node, registry.mapping);
     }
     if (node.isConst) {
       analyzeConstantDeferred(node);
+
+      // TODO(johnniwinther): Compute this in the [ConstructorResolver].
+      // Check that the constructor is not deferred.
+      Send send = node.send.selector.asSend();
+      if (send != null) {
+        // Of the form `const a.b(...)`.
+        if (compiler.deferredLoadTask.deferredPrefixElement(
+                send, registry.mapping) != null) {
+          // `a` is a deferred prefix.
+          isValidAsConstant = false;
+          // TODO(johnniwinther): Create an [ErroneousConstantExpression] here
+          // when constants are only created during resolution.
+        }
+      }
+
       if (isValidAsConstant &&
           constructor.isConst &&
           argumentsResult.isValidAsConstant) {
         CallStructure callStructure = argumentsResult.callStructure;
         List<ConstantExpression> arguments = argumentsResult.constantArguments;
         ConstructedConstantExpression constant =
             new ConstructedConstantExpression(
                 type,
                 constructor,
                 callStructure,
@@ skipping 743 matching lines @@
     }
     return const NoneResult();
   }
 }
 
 /// Looks up [name] in [scope] and unwraps the result.
 Element lookupInScope(Compiler compiler, Node node,
                       Scope scope, String name) {
   return Elements.unwrap(scope.lookup(name), compiler, node);
 }