title: How can I set the language_in option for the Closure compiler?
body: <p>I need to set the language_in option on the Closure compiler to prevent the IE8 parse error: </p>
  
  <p>ERROR - Parse error. IE8 (and below) will parse trailing commas in array and object literals incorrectly. If you are targeting newer versions of JS, set the appropriate language_in option.</p>
  
  <p>I did find a post in the closure group relating to this, however, the option is set directly on the java compiler, rather than through one of the build scripts. I need to be able to set it on a build script. </p>
  
  <p>I'm looking at the scripts in closure/bin/build/ and there are several there. I tried adding the option to closure builder, but it failed.</p>
  
  <p>Can someone direct me about how to set this option correctly?</p>
  
  <p>Thank you.</p>