Missing global attributes in IE9

[Alan Zhang]

IE9 have all four attributes and pass the following test, but it shouldn't because it doesn't have scrollX and scrollY.

es5-polyfill/dist/polyfill.js

Lines 1119 to 1121 in 3f186b5

 if ('innerWidth' in global && 'innerHeight' in global && 'pageXOffset' in global && 'pageYOffset' in global) { 
   return; 
 } 

According to this snippet, the polyfill complete six global attributes instead of four. I suggest we test all attributes it affected to make IE9 environment more flat.

es5-polyfill/dist/polyfill.js

Lines 1134 to 1157 in 3f186b5

 Object.defineProperties(global, { 
   innerWidth: { 
     get: function () { 
       return docEl.clientWidth; 
     } 
   }, 
   innerHeight: { 
     get: function () { 
       return docEl.clientHeight; 
     } 
   }, 
   pageXOffset: { 
     get: scrollX 
   }, 
   pageYOffset: { 
     get: scrollY 
   }, 
   scrollX: { 
     get: scrollX 
   }, 
   scrollY: { 
     get: scrollY 
   } 
 });