Only attempt to do type inference on fields that lack a declared type.

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 10 matching lines @@
         MapLiteral,
         MethodInvocation,
         ProcedureKind,
         ReturnStatement,
         StaticGet,
         StringLiteral,
         SuperInitializer,
         ThisExpression,
         VariableGet;
 
-import 'package:front_end/src/scanner/token.dart' show Token;
-
 import '../modifier.dart' show constMask, finalMask, staticMask;
 
 import '../names.dart' show indexGetName;
 
 import '../source/source_class_builder.dart' show SourceClassBuilder;
 
 import 'kernel_builder.dart'
     show
         Builder,
         EnumBuilder,
@@ skipping 70 matching lines @@
     ///     metadata class E {
     ///       final int index;
     ///       const E(this.index);
     ///       static const E id0 = const E(0);
     ///       ...
     ///       static const E idn-1 = const E(n - 1);
     ///       static const List<E> values = const <E>[id0, ..., idn-1];
     ///       String toString() => { 0: ‘E.id0’, . . ., n-1: ‘E.idn-1’}[index]
     ///     }
     members["index"] = new KernelFieldBuilder(
-        null,
-        intType,
-        "index",
-        finalMask,
-        parent,
-        charOffset,
-        // Synthetic token to signal this field is initialized.
-        new Token.eof(charOffset));
+        null, intType, "index", finalMask, parent, charOffset, null, true);
     KernelConstructorBuilder constructorBuilder = new KernelConstructorBuilder(
         null,
         constMask,
         null,
         "",
         null,
         <FormalParameterBuilder>[
           new KernelFormalParameterBuilder(
               null, 0, intType, "index", true, parent, charOffset)
         ],
         parent,
         charOffset,
         charOffset,
         charEndOffset);
     constructors[""] = constructorBuilder;
     int index = 0;
     List<MapEntry> toStringEntries = <MapEntry>[];
-    KernelFieldBuilder valuesBuilder = new KernelFieldBuilder(
-        null,
-        listType,
-        "values",
-        constMask | staticMask,
-        parent,
-        charOffset,
-        // Synthetic token to signal this field is initialized.
-        new Token.eof(charOffset));
+    KernelFieldBuilder valuesBuilder = new KernelFieldBuilder(null, listType,
+        "values", constMask | staticMask, parent, charOffset, null, true);
     members["values"] = valuesBuilder;
     KernelProcedureBuilder toStringBuilder = new KernelProcedureBuilder(
         null,
         0,
         stringType,
         "toString",
         null,
         null,
         ProcedureKind.Method,
         parent,
@@ skipping 11 matching lines @@
         continue;
       }
       if (name == className) {
         parent.addCompileTimeError(
             charOffset,
             "Name of enum constant '$name' can't be the same as the enum's "
             "own name.");
         constantNamesAndOffsets[i] = null;
         continue;
       }
-      KernelFieldBuilder fieldBuilder = new KernelFieldBuilder(
-          null,
-          selfType,
-          name,
-          constMask | staticMask,
-          parent,
-          charOffset,
-          // Synthetic token to signal this field is initialized.
-          new Token.eof(charOffset));
+      KernelFieldBuilder fieldBuilder = new KernelFieldBuilder(null, selfType,
+          name, constMask | staticMask, parent, charOffset, null, true);
       members[name] = fieldBuilder;
       toStringEntries.add(new MapEntry(
           new IntLiteral(index), new StringLiteral("$className.$name")));
       index++;
     }
     MapLiteral toStringMap = new MapLiteral(toStringEntries, isConst: true);
     KernelEnumBuilder enumBuilder = new KernelEnumBuilder.internal(
         metadata,
         name,
         new Scope(members, null, parent.scope, isModifiable: false),
@@ skipping 94 matching lines @@
     }
     return super.build(libraryBuilder, coreLibrary);
   }
 
   @override
   Builder findConstructorOrFactory(
       String name, int charOffset, Uri uri, LibraryBuilder library) {
     return null;
   }
 }