Use the typedef arity to know how to invoke a closure given by the dom.

dart/lib/compiler/implementation/compiler.dart

Index: dart/lib/compiler/implementation/compiler.dart
===================================================================
--- dart/lib/compiler/implementation/compiler.dart	(revision 8049)
+++ dart/lib/compiler/implementation/compiler.dart	(working copy)
@@ -440,6 +440,17 @@
                               () => resolver.resolveSignature(element));
   }
 
+  FunctionSignature resolveTypedef(TypedefElement element) {
+    return withCurrentElement(element,
+                              () => resolver.resolveTypedef(element));
+  }
+
+  FunctionType computeFunctionType(Element element,
+                                   FunctionSignature signature) {
+    return withCurrentElement(element,
+        () => resolver.computeFunctionType(element, signature));
+  }
+
   Constant compileVariable(VariableElement element) {
     return withCurrentElement(element, () {
       return constantHandler.compileVariable(element);