Add types to shift operations

test/generated_sdk/lib/_internal/compiler/js_lib/js_number.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.
 
 part of _interceptors;
 
 /**
  * The super interceptor class for [JSInt] and [JSDouble]. The compiler
  * recognizes this class as an interceptor, and changes references to
  * [:this:] to actually use the receiver of the method, which is
@@ skipping 375 matching lines @@
     // trick to remove one instruction in the first line.
 
     i = _shru(i, 0) - (_shru(i, 1) & 0x55555555);
     i = (i & 0x33333333) + (_shru(i, 2) & 0x33333333);
     i = 0x0F0F0F0F & (i + _shru(i, 4));
     i += _shru(i, 8);
     i += _shru(i, 16);
     return (i & 0x0000003F);
   }
 
-  static _shru(int value, int shift) => JS('int', '# >>> #', value, shift);
-  static _shrs(int value, int shift) => JS('int', '# >> #', value, shift);
-  static _ors(int a, int b) => JS('int', '# | #', a, b);
+  static int _shru(int value, int shift) => JS('int', '# >>> #', value, shift);

[Jennifer Messerly, 2015/05/20 17:50:19]

wow. I guess dart2js infers so they didn't really care whether it was written
here. Interestingly, the inferred type for them would be more precise too, since
'int' means not null in their type system.

+  static int _shrs(int value, int shift) => JS('int', '# >> #', value, shift);
+  static int _ors(int a, int b) => JS('int', '# | #', a, b);
 
   // Assumes i is <= 32-bit
   static int _spread(int i) {
     i = _ors(i, _shrs(i, 1));
     i = _ors(i, _shrs(i, 2));
     i = _ors(i, _shrs(i, 4));
     i = _ors(i, _shrs(i, 8));
     i = _shru(_ors(i, _shrs(i, 16)), 0);
     return i;
   }
 
   Type get runtimeType => int;
 
   int operator ~() => JS('JSUInt32', r'(~#) >>> 0', this);
 }
 
 class JSDouble extends JSNumber implements double {
   const JSDouble();
   Type get runtimeType => double;
 }
 
 class JSPositiveInt extends JSInt {}
 class JSUInt32 extends JSPositiveInt {}
 class JSUInt31 extends JSUInt32 {}