Make object file names for cl.exe and link.exe.

def make_objs(names, out_dir=''):
        """
        Make object file names for cl.exe and link.exe.
        """
        objs = [replace_ext(name, '.obj') for name in names]
        if out_dir:
            objs = [os.path.join(out_dir, obj) for obj in objs]
        return objs