FIXED: callProlog(): make sure exception term handle remains valid.
FIXED: callProlog(): make sure exception term handle remains valid.

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