Issue 28580. Relax instantiate to bounds.

pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/context/declared_variables.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
@@ skipping 495 matching lines @@
       if (!e.isSynthetic) {
         e.type;
       }
     }
 
     new DeclarationResolver().resolve(unit, unitElement);
 
     // TODO(scheglov) remove EnumMemberBuilder class
 
     new TypeParameterBoundsResolver(
-            _typeProvider, _libraryElement, source, errorListener)
+            _context.typeSystem, _libraryElement, source, errorListener)
         .resolveTypeBounds(unit);
 
     unit.accept(new TypeResolverVisitor(
         _libraryElement, source, _typeProvider, errorListener));
 
     LibraryScope libraryScope = new LibraryScope(_libraryElement);
     unit.accept(new VariableResolverVisitor(
         _libraryElement, source, _typeProvider, errorListener,
         nameScope: libraryScope));
 
@@ skipping 234 matching lines @@
 }
 
 /**
  * Either the name or the source associated with a part-of directive.
  */
 class _NameOrSource {
   final String name;
   final Source source;
   _NameOrSource(this.name, this.source);
 }