Recover from bad supertypes.

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,
         AsyncMarker,
@@ skipping 156 matching lines @@
     members.forEach((String name, dynamic b) {
       MemberBuilder builder = b;
       builder.parent = enumBuilder;
     });
     selfType.builder = enumBuilder;
     return enumBuilder;
   }
 
   KernelTypeBuilder get mixedInType => null;
 
-  InterfaceType buildType(List<KernelTypeBuilder> arguments) {
+  InterfaceType buildType(
+      LibraryBuilder library, List<KernelTypeBuilder> arguments) {
     return cls.rawType;
   }
 
   Class build(KernelLibraryBuilder libraryBuilder) {
     if (constants.isEmpty) {
       libraryBuilder.addCompileTimeError(
           -1, "An enum declaration can't be empty.");
     }
-    toStringMap.keyType = intType.build();
-    toStringMap.valueType = stringType.build();
+    toStringMap.keyType = intType.build(libraryBuilder);
+    toStringMap.valueType = stringType.build(libraryBuilder);
     KernelFieldBuilder indexFieldBuilder = members["index"];
-    Field indexField = indexFieldBuilder.build(libraryBuilder.library);
+    Field indexField = indexFieldBuilder.build(libraryBuilder);
     KernelProcedureBuilder toStringBuilder = members["toString"];
     toStringBuilder.body = new ReturnStatement(new MethodInvocation(
         toStringMap,
         new Name("[]"),
         new Arguments(<Expression>[
           new DirectPropertyGet(new ThisExpression(), indexField)
         ])));
     List<Expression> values = <Expression>[];
     for (String name in constants) {
       KernelFieldBuilder builder = members[name];
-      values.add(new StaticGet(builder.build(libraryBuilder.library)));
+      values.add(new StaticGet(builder.build(libraryBuilder)));
     }
     KernelFieldBuilder valuesBuilder = members["values"];
-    valuesBuilder.build(libraryBuilder.library);
+    valuesBuilder.build(libraryBuilder);
     valuesBuilder.initializer =
         new ListLiteral(values, typeArgument: cls.rawType, isConst: true);
     KernelConstructorBuilder constructorBuilder = members[""];
-    Constructor constructor = constructorBuilder.build(libraryBuilder.library);
+    Constructor constructor = constructorBuilder.build(libraryBuilder);
     constructor.initializers.insert(
         0,
         new FieldInitializer(indexField,
             new VariableGet(constructor.function.positionalParameters.single))
           ..parent = constructor);
     int index = 0;
     for (String constant in constants) {
       KernelFieldBuilder field = members[constant];
-      field.build(libraryBuilder.library);
+      field.build(libraryBuilder);
       Arguments arguments =
           new Arguments(<Expression>[new IntLiteral(index++)]);
       field.initializer =
           new ConstructorInvocation(constructor, arguments, isConst: true);
     }
     return super.build(libraryBuilder);
   }
 
   Builder findConstructorOrFactory(String name) => null;
 }