Revert "use new term_attvars/2"
Revert "use new term_attvars/2"

This reverts commit 404b7906661e1907ff11b832e8342b386a1efe52.

term_attvars/2 currently crashes on OSX.

jn7163/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,mndrix/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel