Add guards to usage of Py_SIZE to check sign of PyLong
Add guards to usage of Py_SIZE to check sign of PyLong

hhsprings/cython,mrGeen/cython,c-blake/cython,slonik-az/cython,hhsprings/cython,encukou/cython,JelleZijlstra/cython,slonik-az/cython,slonik-az/cython,fabianrost84/cython,cython/cython,madjar/cython,achernet/cython,encukou/cython,fabianrost84/cython,roxyboy/cython,fperez/cython,andreasvc/cython,da-woods/cython,dahebolangkuan/cython,mcanthony/cython,dahebolangkuan/cython,da-woods/cython,da-woods/cython,acrispin/cython,fperez/cython,mcanthony/cython,JelleZijlstra/cython,ChristopherHogan/cython,fperez/cython,acrispin/cython,andreasvc/cython,marscher/cython,mrGeen/cython,dahebolangkuan/cython,madjar/cython,JelleZijlstra/cython,hickford/cython,achernet/cython,achernet/cython,achernet/cython,encukou/cython,fperez/cython,dahebolangkuan/cython,roxyboy/cython,madjar/cython,mrGeen/cython,dahebolangkuan/cython,madjar/cython,cython/cython,cython/cython,hickford/cython,scoder/cython,slonik-az/cython,roxyboy/cython,c-blake/cython,c-blake/cython,encukou/cython,marscher/cython,fabianrost84/cython,mcanthony/cython,encukou/cython,acrispin/cython,fabianrost84/cython,c-blake/cython,hickford/cython,hhsprings/cython,achernet/cython,roxyboy/cython,c-blake/cython,hickford/cython,slonik-az/cython,da-woods/cython,mrGeen/cython,scoder/cython,acrispin/cython,madjar/cython,JelleZijlstra/cython,ChristopherHogan/cython,marscher/cython,andreasvc/cython,mrGeen/cython,JelleZijlstra/cython,hickford/cython,hhsprings/cython,marscher/cython,scoder/cython,mcanthony/cython,ChristopherHogan/cython,fabianrost84/cython,marscher/cython,cython/cython,scoder/cython,andreasvc/cython,hhsprings/cython,roxyboy/cython,fperez/cython,andreasvc/cython,acrispin/cython,mcanthony/cython