Fix bug where constants were not correctly canonicalized.

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 595 matching lines @@
 
   String getNameForConstant(Constant constant) {
     return compiledConstants[constant];
   }
 
   StringBuffer writeJsCode(StringBuffer buffer, Constant value) {
     value.writeJsCode(buffer, this);
     return buffer;
   }
 
+  StringBuffer writeCanonicalizedJsCode(StringBuffer buffer, Constant value) {

[ngeoffray, 2012/03/30 08:28:32]

How about using this as the only entry point for writing a constant? So
everything outside this file would do:

compiler.constantHandler.writeConstant(value, buffer).

Then this method would dispatch to constant.writeCanonicalizedJsCode. 

Also, how about making writeJsCode and writeCanonicalizedJsCode on the Constant
classes private? Even if that file is not a library, it will be a strong
indication that it should not be used directly.

[floitsch, 2012/03/30 18:11:49]

Done.

+    value.writeCanonicalizedJsCode(buffer, this);
+    return buffer;
+  }
+
   StringBuffer writeJsCodeForVariable(StringBuffer buffer,
                                       VariableElement element) {
     if (!initialVariableValues.containsKey(element)) {
       compiler.internalError("No initial value for given element",
                              element: element);
     }
     Constant constant = initialVariableValues[element];
-    if (constant.isObject()) {
-      String name = compiledConstants[constant];
-      buffer.add("${compiler.namer.ISOLATE}.prototype.$name");
-    } else {
-      writeJsCode(buffer, constant);
-    }
+    constant.writeCanonicalizedJsCode(buffer, this);
     return buffer;
   }
 
   /**
    * Write the contents of the quoted string to a [StringBuffer] in
    * a form that is valid as JavaScript string literal content.
    * The string is assumed quoted by single quote characters.
    */
   static void writeEscapedString(DartString string,
                                  StringBuffer buffer,
@@ skipping 485 matching lines @@
       Constant fieldValue = fieldValues[field];
       if (fieldValue === null) {
         // Use the default value.
         fieldValue = compiler.compileVariable(field);
       }
       jsNewArguments.add(fieldValue);          
     });
     return jsNewArguments;
   }
 }