[HEIMDAL-646] malloc(0) checks for AIX
[HEIMDAL-646] malloc(0) checks for AIX

madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal