Recover from bad supertypes.

pkg/front_end/lib/src/fasta/source/source_class_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.source_class_builder;
 
 import 'package:kernel/ast.dart'
     show Class, Constructor, Supertype, TreeNode, setParents;
 
 import '../errors.dart' show internalError;
@@ skipping 67 matching lines @@
       count += cls.typeParameters.length;
     }
     return count + super.resolveTypes(library);
   }
 
   Class build(KernelLibraryBuilder library) {
     void buildBuilder(Builder builder) {
       if (builder is KernelFieldBuilder) {
         // TODO(ahe): It would be nice to have a common interface for the build
         // method to avoid duplicating these two cases.
-        cls.addMember(builder.build(library.library));
+        cls.addMember(builder.build(library));
       } else if (builder is KernelFunctionBuilder) {
-        cls.addMember(builder.build(library.library));
+        cls.addMember(builder.build(library));
       } else {
         internalError("Unhandled builder: ${builder.runtimeType}");
       }
     }
 
     members.forEach((String name, Builder builder) {
       do {
         buildBuilder(builder);
         builder = builder.next;
       } while (builder != null);
     });
-    cls.supertype = supertype?.buildSupertype();
-    cls.mixedInType = mixedInType?.buildSupertype();
+    cls.supertype = supertype?.buildSupertype(library);
+    cls.mixedInType = mixedInType?.buildSupertype(library);
     // TODO(ahe): If `cls.supertype` is null, and this isn't Object, report a
     // compile-time error.
     cls.isAbstract = isAbstract;
     if (interfaces != null) {
       for (KernelTypeBuilder interface in interfaces) {
-        Supertype supertype = interface.buildSupertype();
+        Supertype supertype = interface.buildSupertype(library);
         if (supertype != null) {
           // TODO(ahe): Report an error if supertype is null.
           cls.implementedTypes.add(supertype);
         }
       }
     }
     return cls;
   }
 
   Builder findConstructorOrFactory(String name) => constructors[name];
@@ skipping 22 matching lines @@
 Map<String, Builder> computeConstructors(Map<String, Builder> members) {
   Map<String, Builder> constructors = <String, Builder>{};
   members.forEach((String name, Builder builder) {
     if (builder is ProcedureBuilder &&
         (builder.isConstructor || builder.isFactory)) {
       constructors[name] = builder;
     }
   });
   return constructors;
 }