Fix ParameterMirror.hasDefaultValue/defaultValue in source mirrors.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

 // Copyright (c) 2012, 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.
 
 part of resolution;
 
 abstract class TreeElements {
   Element get currentElement;
   Setlet<Node> get superUses;
 
@@ skipping 308 matching lines @@
         redirection = redirection.patch;
       }
       redirection = resolver.visitor.resolveConstructorRedirection(redirection);
     }
   }
 
   void checkMatchingPatchParameters(FunctionElement origin,
                                     Link<Element> originParameters,
                                     Link<Element> patchParameters) {
     while (!originParameters.isEmpty) {
-      Element originParameter = originParameters.head;
-      Element patchParameter = patchParameters.head;
+      VariableElementX originParameter = originParameters.head;
+      VariableElementX patchParameter = patchParameters.head;
+      assert(invariant(originParameter, originParameter.origin == null));
+      assert(invariant(originParameter, originParameter.patch == null));
+      originParameter.patch = patchParameter;
+      assert(invariant(patchParameter, patchParameter.origin == null));
+      assert(invariant(patchParameter, patchParameter.patch == null));
+      patchParameter.origin = originParameter;
       // Hack: Use unparser to test parameter equality. This only works because
       // we are restricting patch uses and the approach cannot be used
       // elsewhere.
       String originParameterText =
           originParameter.parseNode(compiler).toString();
       String patchParameterText =
           patchParameter.parseNode(compiler).toString();
       if (originParameterText != patchParameterText
           // We special case the list constructor because of the
           // optional parameter.
@@ skipping 4164 matching lines @@
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }
 
 /// Looks up [name] in [scope] and unwraps the result.
 Element lookupInScope(Compiler compiler, Node node,
                       Scope scope, String name) {
   return Elements.unwrap(scope.lookup(name), compiler, node);
 }