Use cmp_to_key(Basic.compare) in _addsort, like _mulsort in mul.py
Use cmp_to_key(Basic.compare) in _addsort, like _mulsort in mul.py

moble/sympy,kaushik94/sympy,meghana1995/sympy,lindsayad/sympy,souravsingh/sympy,Davidjohnwilson/sympy,toolforger/sympy,bukzor/sympy,garvitr/sympy,ChristinaZografou/sympy,grevutiu-gabriel/sympy,mafiya69/sympy,saurabhjn76/sympy,mcdaniel67/sympy,debugger22/sympy,abhiii5459/sympy,kaichogami/sympy,kaichogami/sympy,drufat/sympy,farhaanbukhsh/sympy,Sumith1896/sympy,sunny94/temp,madan96/sympy,oliverlee/sympy,kumarkrishna/sympy,drufat/sympy,kaushik94/sympy,vipulroxx/sympy,atreyv/sympy,MechCoder/sympy,souravsingh/sympy,jamesblunt/sympy,sunny94/temp,diofant/diofant,MechCoder/sympy,Vishluck/sympy,rahuldan/sympy,Shaswat27/sympy,ahhda/sympy,cswiercz/sympy,shipci/sympy,Sumith1896/sympy,iamutkarshtiwari/sympy,cccfran/sympy,meghana1995/sympy,kaichogami/sympy,skidzo/sympy,iamutkarshtiwari/sympy,sunny94/temp,aktech/sympy,abloomston/sympy,wyom/sympy,beni55/sympy,debugger22/sympy,AkademieOlympia/sympy,cswiercz/sympy,grevutiu-gabriel/sympy,cswiercz/sympy,toolforger/sympy,iamutkarshtiwari/sympy,chaffra/sympy,liangjiaxing/sympy,sahmed95/sympy,Davidjohnwilson/sympy,Arafatk/sympy,souravsingh/sympy,madan96/sympy,mafiya69/sympy,wanglongqi/sympy,Titan-C/sympy,VaibhavAgarwalVA/sympy,garvitr/sympy,jamesblunt/sympy,oliverlee/sympy,skidzo/sympy,shipci/sympy,asm666/sympy,garvitr/sympy,jamesblunt/sympy,jerli/sympy,toolforger/sympy,Gadal/sympy,moble/sympy,liangjiaxing/sympy,MridulS/sympy,beni55/sympy,wanglongqi/sympy,hargup/sympy,skidzo/sympy,Arafatk/sympy,bukzor/sympy,Curious72/sympy,shipci/sympy,jerli/sympy,Designist/sympy,wyom/sympy,pbrady/sympy,wyom/sympy,asm666/sympy,ChristinaZografou/sympy,hargup/sympy,Mitchkoens/sympy,vipulroxx/sympy,ahhda/sympy,postvakje/sympy,pandeyadarsh/sympy,shikil/sympy,postvakje/sympy,VaibhavAgarwalVA/sympy,madan96/sympy,maniteja123/sympy,abhiii5459/sympy,Titan-C/sympy,Designist/sympy,atsao72/sympy,Gadal/sympy,mcdaniel67/sympy,saurabhjn76/sympy,MridulS/sympy,lindsayad/sympy,yashsharan/sympy,postvakje/sympy,yashsharan/sympy,MechCoder/sympy,ahhda/sympy,kaushik94/sympy,sahilshekhawat/sympy,sahilshekhawat/sympy,rahuldan/sympy,jaimahajan1997/sympy,farhaanbukhsh/sympy,jerli/sympy,ChristinaZografou/sympy,Vishluck/sympy,rahuldan/sympy,ga7g08/sympy,dqnykamp/sympy,Designist/sympy,sahmed95/sympy,debugger22/sympy,meghana1995/sympy,Mitchkoens/sympy,bukzor/sympy,liangjiaxing/sympy,sahmed95/sympy,abhiii5459/sympy,Sumith1896/sympy,mcdaniel67/sympy,vipulroxx/sympy,yukoba/sympy,Shaswat27/sympy,drufat/sympy,kevalds51/sympy,sahilshekhawat/sympy,jbbskinny/sympy,aktech/sympy,sampadsaha5/sympy,AkademieOlympia/sympy,cccfran/sympy,emon10005/sympy,kevalds51/sympy,Mitchkoens/sympy,jbbskinny/sympy,kumarkrishna/sympy,abloomston/sympy,ga7g08/sympy,pbrady/sympy,mafiya69/sympy,beni55/sympy,VaibhavAgarwalVA/sympy,abloomston/sympy,cccfran/sympy,AunShiLord/sympy,pandeyadarsh/sympy,atreyv/sympy,jbbskinny/sympy,Gadal/sympy,AunShiLord/sympy,grevutiu-gabriel/sympy,maniteja123/sympy,Shaswat27/sympy,maniteja123/sympy,pandeyadarsh/sympy,chaffra/sympy,atsao72/sympy,MridulS/sympy,AunShiLord/sympy,Curious72/sympy,yukoba/sympy,AkademieOlympia/sympy,Davidjohnwilson/sympy,shikil/sympy,Vishluck/sympy,atreyv/sympy,saurabhjn76/sympy,Titan-C/sympy,dqnykamp/sympy,jaimahajan1997/sympy,shikil/sympy,emon10005/sympy,hargup/sympy,asm666/sympy,lindsayad/sympy,kevalds51/sympy,skirpichev/omg,yashsharan/sympy,pbrady/sympy,oliverlee/sympy,atsao72/sympy,Curious72/sympy,chaffra/sympy,yukoba/sympy,sampadsaha5/sympy,ga7g08/sympy,farhaanbukhsh/sympy,aktech/sympy,wanglongqi/sympy,kumarkrishna/sympy,jaimahajan1997/sympy,dqnykamp/sympy,sampadsaha5/sympy,moble/sympy,emon10005/sympy,Arafatk/sympy