Missing global attributes in IE9

[zcfan]

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
	}
	});