Safely call defineProperty when setting array length. (#273)

* wrap setting array length in try catch

Older browsers, such as Firefox 22 and below, throw `new InternalError("defining the length property on an array is not currently supported")` when trying to set the length with `defineProperty` so a try catch will allow for those that do support it to use it, while those that don't fail due to the error.

* removed defineProperty for array length and fixed lint error

Author: spencercarnage

dist/Intl.complete.js

@@ -12,7 +12,6 @@ import {
 } from './9.negotiation.js';
 
 import {
-    FormatNumberToString,
     SetNumberFormatDigitOptions
 } from './11.numberformat.js';
 

dist/Intl.js

@@ -607,9 +607,7 @@ export function /*9.2.8 */SupportedLocales (availableLocales, requestedLocales,
             writable: false, configurable: false, value: subset[P]
         });
     }
-    // "Freeze" the array so no new elements can be added
-    defineProperty(subset, 'length', { writable: false });
-
+    
     // 5. Return subset
     return subset;
 }