Add a compile time error for non-static const fields

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index e1819f00647e8b80e4821e99efd8d973fa525920..a203ff4e119cf3a2e94c3f610989e93161cdc3d1 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -978,8 +978,11 @@ class ResolverTask extends CompilerTask {
           }
         }
         if (member.isField) {
-          if (!member.modifiers.isStatic &&
-              !member.modifiers.isFinal) {
+          if (member.modifiers.isConst && !member.modifiers.isStatic) {
+            compiler.reportError(
+                member, MessageKind.ILLEGAL_CONST_FIELD_MODIFIER);
+          }
+          if (!member.modifiers.isStatic && !member.modifiers.isFinal) {
             nonFinalInstanceFields.add(member);
           }
         }