BufferGeometryLoader: Added comment.

src/loaders/BufferGeometryLoader.js

@@ -93,6 +93,7 @@ Object.assign( BufferGeometryLoader.prototype, {
 var TYPED_ARRAYS = {
 	Int8Array: Int8Array,
 	Uint8Array: Uint8Array,
+	// Workaround for IE11 pre KB2929437. See #11440
 	Uint8ClampedArray: typeof Uint8ClampedArray !== 'undefined' ? Uint8ClampedArray : Uint8Array,
 	Int16Array: Int16Array,
 	Uint16Array: Uint16Array,