Given a typeid, get the information about an opaque type.
function nf90_inq_opaque(ncid, xtype, name, size)
integer, intent(in) :: ncid
integer, intent(in) :: xtype
character (len = *), intent(out) :: name
integer, intent(out) :: size
integer :: nf90_inq_opaque
NCIDXTYPENAMESIZEPNF90_NOERRNF90_EBADTYPEIDNF90_EBADFIELDIDNF90_EHDFERR