FIXED: possible crash when ATOM GC signal is received while handling GC signal
FIXED: possible crash when ATOM GC signal is received while handling GC signal

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