Start propagating non-primitive types in the backend, and fold instructions that know about the typ…

lib/compiler/implementation/compile_time_constants.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.
 
 class Constant implements Hashable {
   const Constant();
 
   bool isNull() => false;
   bool isBool() => false;
   bool isTrue() => false;
@@ skipping 229 matching lines @@
   }
 
   bool operator ==(var other) {
     if (other is !StringConstant) return false;
     StringConstant otherString = other;
     return (_hashCode == otherString._hashCode) && (value == otherString.value);
   }
 
   int hashCode() => _hashCode;
   DartString toDartString() => value;
+  int get length() => value.length;
 }
 
 class ObjectConstant extends Constant {
   final Type type;
 
   ObjectConstant(this.type);
   bool isObject() => true;
 
   // TODO(1603): The class should be marked as abstract, but the VM doesn't
   // currently allow this.
@@ skipping 40 matching lines @@
     if (entries.length != otherList.entries.length) return false;
     for (int i = 0; i < entries.length; i++) {
       if (entries[i] != otherList.entries[i]) return false;
     }
     return true;
   }
 
   int hashCode() => _hashCode;
 
   List<Constant> getDependencies() => entries;
+
+  int get length() => entries.length;
 }
 
 class MapConstant extends ObjectConstant {
   /**
    * The [PROTO_PROPERTY] must not be used as normal property in any JavaScript
    * object. It would change the prototype chain.
    */
   static final String PROTO_PROPERTY = "__proto__";
 
   /** The dart class implementing constant map literals. */
@@ skipping 91 matching lines @@
     return true;
   }
 
   int hashCode() => _hashCode;
 
   List<Constant> getDependencies() {
     List<Constant> result = <Constant>[keys];
     result.addAll(values);
     return result;
   }
+
+  int get length() => keys.length;
 }
 
 class ConstructedConstant extends ObjectConstant {
   final List<Constant> fields;
   int _hashCode;
 
   ConstructedConstant(Type type, this.fields) : super(type) {
     assert(type !== null);
     // TODO(floitsch): create a better hash.
     int hash = 0;
@@ skipping 706 matching lines @@
       Constant fieldValue = fieldValues[field];
       if (fieldValue === null) {
         // Use the default value.
         fieldValue = compiler.compileVariable(field);
       }
       jsNewArguments.add(fieldValue);          
     });
     return jsNewArguments;
   }
 }