Add --no-source-maps flag to dart2js executable

BUG= http://dartbug.com/21299
R=floitsch@google.com, johnniwinther@google.com

Review URL: https://codereview.chromium.org//1074903002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@45071 260f80e4-7a28-3924-810f-c04153c831b5
1 file changed