FIXED: Atom GC could miss atoms that are in a message queue that is not associated to a thread.  Keri Harris.
FIXED: Atom GC could miss atoms that are in a message queue that is
not associated to a thread.  Keri Harris.

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