Add debug names to scopes.

pkg/front_end/lib/src/fasta/kernel/kernel_enum_builder.dart

 // Copyright (c) 2016, 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 fasta.kernel_enum_builder;
 
 import 'package:kernel/ast.dart'
     show
         Arguments,
         Class,
@@ skipping 192 matching lines @@
       members[name] = fieldBuilder;
       toStringEntries.add(new MapEntry(
           new IntLiteral(index), new StringLiteral("$className.$name")));
       index++;
     }
     MapLiteral toStringMap = new MapLiteral(toStringEntries, isConst: true);
     KernelEnumBuilder enumBuilder = new KernelEnumBuilder.internal(
         documentationComment,
         metadata,
         name,
-        new Scope(members, null, parent.scope, isModifiable: false),
-        new Scope(constructors, null, null, isModifiable: false),
+        new Scope(members, null, parent.scope, "enum $name",
+            isModifiable: false),
+        new Scope(constructors, null, null, "constructors",
+            isModifiable: false),
         cls,
         constantNamesAndOffsetsAndDocs,
         toStringMap,
         intType,
         listType,
         objectType,
         stringType,
         parent,
         charOffset);
     // TODO(sigmund): dynamic should be `covariant MemberBuilder`.
@@ skipping 84 matching lines @@
     }
     return super.build(libraryBuilder, coreLibrary);
   }
 
   @override
   Builder findConstructorOrFactory(
       String name, int charOffset, Uri uri, LibraryBuilder library) {
     return null;
   }
 }