foreign decls: use wlkHsSigType, not wlkHsType, since the tysig may
have implicitly quantified tyvars.
U_fobind id ty ext_name unsafe_flag cconv imp_exp srcline ->
mkSrcLocUgn srcline $ \ src_loc ->
wlkVarId id `thenUgn` \ h_id ->
- wlkHsType ty `thenUgn` \ h_ty ->
+ wlkHsSigType ty `thenUgn` \ h_ty ->
wlkExtName ext_name `thenUgn` \ h_ext_name ->
rdCallConv cconv `thenUgn` \ h_cconv ->
rdForKind imp_exp (cvFlag unsafe_flag) `thenUgn` \ h_imp_exp ->