Fix the OSX failures in this test -- they were due to /tmp being a symlink

to /private/tmp.  Adding a call to os.path.realpath() to temp_dir() fixed it.

Lib/test/test_cmd_line_script.py

@@ -29,6 +29,7 @@ def _run_python(*args):
 @contextlib.contextmanager
 def temp_dir():
     dirname = tempfile.mkdtemp()
+    dirname = os.path.realpath(dirname)
     try:
         yield dirname
     finally: