TEST="out/ia32.release/d8 te<tab>" gets completed to "test/" with trailing slash

Review URL: https://chromiumcodereview.appspot.com/9363025

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10649 ce2b1a6d-e550-0410-aec6-3dcde31c8c00