Dart2js option to dump info about compilation

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

 // Copyright (c) 2013, 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 elements.modelx;
 
 import 'elements.dart';
 import '../../compiler.dart' as api;
 import '../tree/tree.dart';
 import '../util/util.dart';
@@ skipping 315 matching lines @@
     throw 'unsupported operation on erroneous element';
   }
 
   Link<MetadataAnnotation> get metadata => unsupported();
   get type => unsupported();
   get cachedNode => unsupported();
   get functionSignature => unsupported();
   get patch => null;
   get origin => this;
   get defaultImplementation => unsupported();
+  get nestedClosures => unsupported();
 
   bool get isRedirectingFactory => unsupported();
 
   setPatch(patch) => unsupported();
   computeSignature(compiler) => unsupported();
   requiredParameterCount(compiler) => unsupported();
   optionalParameterCount(compiler) => unsupported();
   parameterCount(compiler) => unsupported();
 
   // TODO(kasperl): These seem unnecessary.
@@ skipping 767 matching lines @@
 
   accept(ElementVisitor visitor) => visitor.visitTypedefElement(this);
 }
 
 class VariableElementX extends ElementX implements VariableElement {
   final VariableListElement variables;
   Expression cachedNode; // The send or the identifier in the variables list.
 
   Modifiers get modifiers => variables.modifiers;
 
+  List<FunctionElement> nestedClosures = new List<FunctionElement>();
+
   VariableElementX(String name,
                    VariableListElement variables,
                    ElementKind kind,
                    this.cachedNode)
     : this.variables = variables,
       super(name, kind, variables.enclosingElement);
 
   VariableElementX.synthetic(String name,
       ElementKind kind,
       Element enclosing) :
@@ skipping 280 matching lines @@
     }
     return true;
   }
 }
 
 class FunctionElementX extends ElementX implements FunctionElement {
   FunctionExpression cachedNode;
   DartType type;
   final Modifiers modifiers;
 
+  List<FunctionElement> nestedClosures = new List<FunctionElement>();
+
   FunctionSignature functionSignature;
 
   /**
    * A function declaration that should be parsed instead of the current one.
    * The patch should be parsed as if it was in the current scope. Its
    * signature must match this function's signature.
    */
   FunctionElement patch = null;
   FunctionElement origin = null;
 
@@ skipping 981 matching lines @@
 
   MetadataAnnotation ensureResolved(Compiler compiler) {
     if (resolutionState == STATE_NOT_STARTED) {
       compiler.resolver.resolveMetadataAnnotation(this);
     }
     return this;
   }
 
   String toString() => 'MetadataAnnotation($value, $resolutionState)';
 }