A small issue in CommentCast function

[Gokulakannan Somasundaram <gokul007(at)gmail(dot)com>]

Hi,
   I think this is more of code uniformity issue. Nevertheless, i just
thought of putting it here.
   In the CommentCast function, i think both sourcetype and targettype
should be in the arguments, whereas in the code, source type is made as the
name and the target type is passed in as argument. So both of them should
get stored in the objargs member of the CommentStmt struct.

Thanks,
Gokul.