Add the tests for the cases that now work.
Add the tests for the cases that now work.

Comments 15 and 16 on Issue 754 show examples of cases which failed
before the changes introduced in the previous commits.

hrashk/sympy,ChristinaZografou/sympy,postvakje/sympy,vipulroxx/sympy,shikil/sympy,debugger22/sympy,sampadsaha5/sympy,yukoba/sympy,MridulS/sympy,skirpichev/omg,mcdaniel67/sympy,abloomston/sympy,Sumith1896/sympy,rahuldan/sympy,cccfran/sympy,Designist/sympy,kaichogami/sympy,AunShiLord/sympy,kaushik94/sympy,kmacinnis/sympy,debugger22/sympy,jerli/sympy,souravsingh/sympy,sampadsaha5/sympy,debugger22/sympy,mcdaniel67/sympy,pbrady/sympy,Arafatk/sympy,lidavidm/sympy,ChristinaZografou/sympy,drufat/sympy,emon10005/sympy,AkademieOlympia/sympy,mafiya69/sympy,iamutkarshtiwari/sympy,shikil/sympy,Designist/sympy,skidzo/sympy,Gadal/sympy,kumarkrishna/sympy,Gadal/sympy,jamesblunt/sympy,kaushik94/sympy,emon10005/sympy,beni55/sympy,bukzor/sympy,atreyv/sympy,Arafatk/sympy,liangjiaxing/sympy,pandeyadarsh/sympy,AkademieOlympia/sympy,postvakje/sympy,Davidjohnwilson/sympy,atreyv/sympy,Vishluck/sympy,asm666/sympy,lidavidm/sympy,jaimahajan1997/sympy,MechCoder/sympy,flacjacket/sympy,oliverlee/sympy,amitjamadagni/sympy,pbrady/sympy,lindsayad/sympy,garvitr/sympy,jamesblunt/sympy,chaffra/sympy,aktech/sympy,moble/sympy,sahmed95/sympy,wanglongqi/sympy,madan96/sympy,meghana1995/sympy,chaffra/sympy,Sumith1896/sympy,ga7g08/sympy,pandeyadarsh/sympy,rahuldan/sympy,skidzo/sympy,Curious72/sympy,hargup/sympy,bukzor/sympy,srjoglekar246/sympy,sunny94/temp,Curious72/sympy,grevutiu-gabriel/sympy,Shaswat27/sympy,farhaanbukhsh/sympy,cccfran/sympy,aktech/sympy,AkademieOlympia/sympy,maniteja123/sympy,toolforger/sympy,sunny94/temp,sahilshekhawat/sympy,lindsayad/sympy,mafiya69/sympy,toolforger/sympy,ga7g08/sympy,shikil/sympy,wyom/sympy,drufat/sympy,madan96/sympy,Mitchkoens/sympy,Designist/sympy,MridulS/sympy,AunShiLord/sympy,Vishluck/sympy,sampadsaha5/sympy,yashsharan/sympy,grevutiu-gabriel/sympy,pbrady/sympy,sahilshekhawat/sympy,drufat/sympy,Titan-C/sympy,cccfran/sympy,ga7g08/sympy,sahmed95/sympy,maniteja123/sympy,jaimahajan1997/sympy,saurabhjn76/sympy,dqnykamp/sympy,cswiercz/sympy,Titan-C/sympy,souravsingh/sympy,vipulroxx/sympy,kevalds51/sympy,kmacinnis/sympy,jamesblunt/sympy,amitjamadagni/sympy,garvitr/sympy,MechCoder/sympy,atsao72/sympy,wyom/sympy,aktech/sympy,kaichogami/sympy,atsao72/sympy,jbbskinny/sympy,oliverlee/sympy,chaffra/sympy,beni55/sympy,jaimahajan1997/sympy,hrashk/sympy,yashsharan/sympy,shipci/sympy,farhaanbukhsh/sympy,dqnykamp/sympy,AunShiLord/sympy,mafiya69/sympy,saurabhjn76/sympy,iamutkarshtiwari/sympy,sahilshekhawat/sympy,liangjiaxing/sympy,sunny94/temp,vipulroxx/sympy,asm666/sympy,yashsharan/sympy,ahhda/sympy,pandeyadarsh/sympy,jbbskinny/sympy,garvitr/sympy,hargup/sympy,Shaswat27/sympy,jerli/sympy,wyom/sympy,shipci/sympy,abhiii5459/sympy,moble/sympy,Davidjohnwilson/sympy,Arafatk/sympy,cswiercz/sympy,kevalds51/sympy,meghana1995/sympy,atsao72/sympy,mcdaniel67/sympy,Mitchkoens/sympy,abloomston/sympy,grevutiu-gabriel/sympy,iamutkarshtiwari/sympy,VaibhavAgarwalVA/sympy,VaibhavAgarwalVA/sympy,Shaswat27/sympy,MechCoder/sympy,jbbskinny/sympy,kumarkrishna/sympy,hargup/sympy,Sumith1896/sympy,bukzor/sympy,abhiii5459/sympy,yukoba/sympy,cswiercz/sympy,diofant/diofant,emon10005/sympy,ahhda/sympy,hrashk/sympy,moble/sympy,toolforger/sympy,lindsayad/sympy,wanglongqi/sympy,postvakje/sympy,VaibhavAgarwalVA/sympy,MridulS/sympy,kevalds51/sympy,Gadal/sympy,farhaanbukhsh/sympy,beni55/sympy,wanglongqi/sympy,yukoba/sympy,liangjiaxing/sympy,shipci/sympy,lidavidm/sympy,souravsingh/sympy,Titan-C/sympy,skidzo/sympy,madan96/sympy,sahmed95/sympy,dqnykamp/sympy,kumarkrishna/sympy,kaichogami/sympy,atreyv/sympy,Curious72/sympy,Davidjohnwilson/sympy,kaushik94/sympy,kmacinnis/sympy,jerli/sympy,ChristinaZografou/sympy,Mitchkoens/sympy,meghana1995/sympy,rahuldan/sympy,saurabhjn76/sympy,ahhda/sympy,asm666/sympy,maniteja123/sympy,abloomston/sympy,abhiii5459/sympy,Vishluck/sympy,oliverlee/sympy