cpsir: insert guard and force specialization for [] and []=

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 1105 matching lines @@
       case BuiltinOperator.LooseNeq:
         return new js.Binary('!=', args[0], args[1]);
       case BuiltinOperator.IsFalsy:
         return new js.Prefix('!', args[0]);
       case BuiltinOperator.IsNumber:
         return js.js('typeof # === "number"', args);
       case BuiltinOperator.IsNotNumber:
         return js.js('typeof # !== "number"', args);
       case BuiltinOperator.IsFloor:
         return js.js('Math.floor(#) === #', args);
-      case BuiltinOperator.IsNumberAndFloor:
+      case BuiltinOperator.IsInteger:
         return js.js('typeof # === "number" && Math.floor(#) === #', args);
+      case BuiltinOperator.IsNotInteger:
+        return js.js('typeof # !== "number" || Math.floor(#) !== #', args);
       case BuiltinOperator.IsFixedLengthJSArray:
         // TODO(sra): Remove boolify (i.e. !!).
         return js.js(r'!!#.fixed$length', args);
       case BuiltinOperator.IsExtendableJSArray:
         return js.js(r'!#.fixed$length', args);
       case BuiltinOperator.IsModifiableJSArray:
         return js.js(r'!#.immutable$list', args);
       case BuiltinOperator.IsUnmodifiableJSArray:
         // TODO(sra): Remove boolify (i.e. !!).
         return js.js(r'!!#.immutable$list', args);
@@ skipping 99 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);
     });
   }
 }