When using SDK outline, transplant its names into the name root.

pkg/kernel/lib/canonical_name.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 kernel.canonical_name;
 
 import 'ast.dart';
 
 /// A string sequence that identifies a library, class, or member.
 ///
 /// Canonical names are organized in a prefix tree.  Each node knows its
@@ skipping 39 matching lines @@
 ///         "@factories"
 ///         Qualified name
 ///
 ///      Qualified name:
 ///         if private: URI of library
 ///         Name text
 ///
 /// The "qualified name" allows a member to have a name that is private to
 /// a library other than the one containing that member.
 class CanonicalName {
-  final CanonicalName parent;
+  CanonicalName _parent;
   final String name;
 
   Map<String, CanonicalName> _children;
 
   /// The library, class, or member bound to this name.
   Reference reference;
 
   /// Temporary index used during serialization.
   int index = -1;
 
-  CanonicalName._(this.parent, this.name) {
+  CanonicalName._(this._parent, this.name) {
     assert(name != null);
   }
 
-  CanonicalName.root()
-      : parent = null,
-        name = '';
+  CanonicalName.root() : name = '';
 
   bool get isRoot => parent == null;
 
+  CanonicalName get parent => _parent;
+
   Iterable<CanonicalName> get children =>
       _children?.values ?? const <CanonicalName>[];
 
   CanonicalName getChild(String name) {
     var map = _children ??= <String, CanonicalName>{};
     return map[name] ??= new CanonicalName._(this, name);
   }
 
   CanonicalName getChildFromUri(Uri uri) {
     // Note that the Uri class caches its string representation, and all library
@@ skipping 14 matching lines @@
   }
 
   CanonicalName getChildFromTypedef(Typedef typedef_) {
     return getChild('@typedefs').getChild(typedef_.name);
   }
 
   void removeChild(String name) {
     _children?.remove(name);
   }
 
+  /// Transplant the given [child] into this name.
+  void transplantChild(CanonicalName child) {
+    var map = _children ??= <String, CanonicalName>{};
+    map[child.name] = child;
+    child._parent = this;
+  }
+
   void bindTo(Reference target) {
     if (reference == target) return;
     if (reference != null) {
       throw '$this is already bound';
     }
     if (target.canonicalName != null) {
       throw 'Cannot bind $this to ${target.node}, target is already bound to '
           '${target.canonicalName}';
     }
     target.canonicalName = this;
@@ skipping 29 matching lines @@
     }
     if (member is Field) {
       return '@fields';
     }
     if (member is Constructor) {
       return '@constructors';
     }
     throw 'Unexpected member: $member';
   }
 }