Generate better code for '=='.

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/operations.dart

 // Copyright (c) 2015, 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.
 
 /// This library defines runtime operations on objects used by the code
 /// generator.
 part of dart._runtime;
 
 class InvocationImpl extends Invocation {
   final Symbol memberName;
@@ skipping 530 matching lines @@
   bool result = strongInstanceOf(obj, type, true);
   if (JS('bool', '#', result)) return obj;
   if (JS('bool', '!dart.__ignoreAllErrors')) {
     _throwTypeError(obj, type, result);
   }
   JS('', 'console.error(#)',
       'Actual: ${typeName(getReifiedType(obj))} Expected: ${typeName(type)}');
   return obj;
 }
 
-bool test(obj) {
-  if (obj is bool) return obj;
-  return booleanConversionFailed(obj);
+bool test(bool obj) {
+  if (obj == null) _throwBooleanConversionError();
+  return obj;
 }
 
-bool booleanConversionFailed(obj) {
+bool dtest(obj) {
+  if (obj is! bool) booleanConversionFailed(obj);
+  return obj;
+}
+
+void _throwBooleanConversionError() =>
+    throw new BooleanConversionAssertionError();
+
+void booleanConversionFailed(obj) {
   if (obj == null) {
-    throw new BooleanConversionAssertionError();
+    _throwBooleanConversionError();
   }
   var actual = getReifiedType(obj);
   var expected = JS('', '#', bool);
   throw new TypeErrorImplementation.fromMessage(
       "type '${typeName(actual)}' is not a subtype of "
       "type '${typeName(expected)}' in boolean expression");
 }
 
 void _throwCastError(obj, type, bool result) {
   var actual = getReifiedType(obj);
@@ skipping 426 matching lines @@
     JS('', '# = "+" + #', name, name);
   }
   return name;
 }
 
 /// Emulates the implicit "loadLibrary" function provided by a deferred library.
 ///
 /// Libraries are not actually deferred in DDC, so this just returns a future
 /// that completes immediately.
 Future loadLibrary() => new Future.value();