When creating the "ref" value constructor use the type variable from the "ref" datatype.  This fixes an oddity where "datatype r = datatype ref" prints as "datatype 'a r = ref of 'b".
When creating the "ref" value constructor use the type variable from the "ref" datatype.  This fixes an oddity where "datatype r = datatype ref" prints as "datatype 'a r = ref of 'b".

git-svn-id: 98787b36aaefbae4b30fa755be920954cd25e1e4@1864 ae7d391e-3f74-4a2b-a0db-a8776840fd2a

dcjm/polyml,polyml/polyml,dcjm/polyml,dcjm/polyml,polyml/polyml,dcjm/polyml,mn200/polyml,mn200/polyml,mn200/polyml,mn200/polyml,polyml/polyml,polyml/polyml