code cleanup in ConstantFolding transform to make boolean handling less error prone
code cleanup in ConstantFolding transform to make boolean handling less error prone

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