dart2js cps: Combine integer type check with bounds check.

pkg/compiler/lib/src/cps_ir/builtin_operator.dart

Index: pkg/compiler/lib/src/cps_ir/builtin_operator.dart
diff --git a/pkg/compiler/lib/src/cps_ir/builtin_operator.dart b/pkg/compiler/lib/src/cps_ir/builtin_operator.dart
index 59812db1e15ad5d7e42b6cb16fb08666e0b541dd..79928219ca22286301be45a45d57c91f73fc6b5a 100644
--- a/pkg/compiler/lib/src/cps_ir/builtin_operator.dart
+++ b/pkg/compiler/lib/src/cps_ir/builtin_operator.dart
@@ -142,6 +142,20 @@ enum BuiltinOperator {
   /// Compiles to `typeof x !== 'number' || Math.floor(x) !== x`
   IsNotInteger,
 
+  /// Returns true if `x` is an unsigned 32-bit integer.
+  ///
+  /// The argument must be repeated 2 times.
+  ///
+  /// Compiles to `x >>> 0 === x`
+  IsUnsigned32BitInteger,
+
+  /// Returns false if `x` is an unsigned 32-bit integer.
+  ///
+  /// The argument must be repeated 2 times.
+  ///
+  /// Compiles to `x >>> 0 !== x`
+  IsNotUnsigned32BitInteger,
+
   /// Returns true if the argument is a fixed length Array.
   ///
   /// Uses one argument.