dart2js cps: Add CharCodeAt builtin.

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

 // Copyright (c) 2014, 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 code_generator;
 
 import 'glue.dart';
 
 import '../../closure.dart' show
     ClosureClassElement;
@@ skipping 932 matching lines @@
       case BuiltinOperator.NumShr:
         // No normalization required since output is always uint32.
         return js.js('# >>> #', args);
       case BuiltinOperator.NumBitNot:
         return js.js('(~#) >>> 0', args);
       case BuiltinOperator.NumNegate:
         return js.js('-#', args);
       case BuiltinOperator.StringConcatenate:
         if (args.isEmpty) return js.string('');
         return args.reduce((e1,e2) => new js.Binary('+', e1, e2));
+      case BuiltinOperator.CharCodeAt:
+        return js.js('#.charCodeAt(#)', args);
       case BuiltinOperator.Identical:
         registry.registerStaticUse(new StaticUse.staticInvoke(
             glue.identicalFunction, new CallStructure.unnamed(args.length)));
         return buildStaticHelperInvocation(glue.identicalFunction, args);
       case BuiltinOperator.StrictEq:
         return new js.Binary('===', args[0], args[1]);
       case BuiltinOperator.StrictNeq:
         return new js.Binary('!==', args[0], args[1]);
       case BuiltinOperator.LooseEq:
         return new js.Binary('==', args[0], args[1]);
@@ skipping 127 matching lines @@
   void registerDefaultParameterValues(ExecutableElement element) {
     if (element is! FunctionElement) return;
     FunctionElement function = element;
     if (function.isStatic) return; // Defaults are inlined at call sites.
     function.functionSignature.forEachOptionalParameter((param) {
       ConstantValue constant = glue.getDefaultParameterValue(param);
       registry.registerCompileTimeConstant(constant);
     });
   }
 }