dart2js: improve ssa utilization of bool value types

tests/compiler/dart2js/source_mapping_test.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.
 
 import 'dart:async';
 import 'package:expect/expect.dart';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/io/code_output.dart';
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/io/source_information.dart';
@@ skipping 50 matching lines @@
   }));
 }
 
 String FUNCTIONS_TEST = '''
 @void main() { print(test(15)); @}
 // The 'if' has been added to avoid inlining of 'test'.
 @int test(int x) { if (x != null) return x; else return null; @}''';
 
 String RETURN_TEST = 'void main() { print(((x) { @return x; })(0)); }';
 
-String NOT_TEST = 'void main() { ((x) { if (@!x) print(x); })(false); }';
+String NOT_TEST = 'void main() { ((x) { if (@!x) print(x); })(1==2); }';
 
 String UNARY_TEST = 'void main() { ((x, y) { print(@-x + @~y); })(1,2); }';
 
 String BINARY_TEST = 'void main() { ((x, y) { if (x @!= y) print(x @* y); })(1,2); }';
 
 String SEND_TEST = '''
 void main() {
   @staticSend(0);
   NewSend o = @new NewSend();
   @o.dynamicSend(0);
@@ skipping 30 matching lines @@
   testSourceMapLocations(FUNCTIONS_TEST);
   testSourceMapLocations(RETURN_TEST);
   testSourceMapLocations(NOT_TEST);
   testSourceMapLocations(UNARY_TEST);
   testSourceMapLocations(BINARY_TEST);
   testSourceMapLocations(SEND_TEST);
   testSourceMapLocations(SEND_SET_TEST);
   testSourceMapLocations(LOOP_TEST);
   testSourceMapLocations(INTERCEPTOR_TEST);
 }