Handle fields with initializers in constant constructors.

pkg/compiler/lib/src/resolution/resolution.dart

Index: pkg/compiler/lib/src/resolution/resolution.dart
diff --git a/pkg/compiler/lib/src/resolution/resolution.dart b/pkg/compiler/lib/src/resolution/resolution.dart
index 2fd4e6850c401ca073c26d2c4e46896373030e91..a5873319efe71c5232b394538e993794ffbab833 100644
--- a/pkg/compiler/lib/src/resolution/resolution.dart
+++ b/pkg/compiler/lib/src/resolution/resolution.dart
@@ -53,6 +53,7 @@ import 'class_members.dart' show MembersCreator;
 import 'constructors.dart';
 import 'members.dart';
 import 'registry.dart';
+import 'resolution_result.dart';
 import 'signatures.dart';
 import 'tree_elements.dart';
 import 'typedefs.dart';
@@ -384,7 +385,10 @@ class ResolverTask extends CompilerTask {
     if (initializer != null) {
       // TODO(johnniwinther): Avoid analyzing initializers if
       // [Compiler.analyzeSignaturesOnly] is set.
-      visitor.visit(initializer);
+      ResolutionResult result = visitor.visit(initializer);
+      if (result.isConstant) {
+        element.constant = result.constant;
+      }
     } else if (modifiers.isConst) {
       reporter.reportErrorMessage(
           element, MessageKind.CONST_WITHOUT_INITIALIZER);