title: iOS System locale identifier is empty
body: <p>I've noticed something weird while using date formatters. Below is the code for the date formatter.</p>
  
  <pre><code>let formatter = NSDateFormatter()
  formatter.dateFormat = "EEE dd MMM h:mm a"
  formatter.locale = NSLocale.systemLocale()
  print(formatter.stringFromDate(NSDate()) )
  </code></pre>
  
  <p>The output is: "Fri 18 M03 1:05 PM". Which is kind of weird. However removing the formatter's locale gives me the output that I want: "Fri 18 Mar 1:05 PM".</p>
  
  <p>I also tried printing out NSLocale.systemLocale(), and the output is an empty string. Is that normal? And what is actually happening to the date formatter when you change the locale? </p>
  
  <p>FYI: I'm testing this on an actual device. And also changing the Region formats in device settings have no affect on the locale identifier.</p>