dsolve: add a temporary FIXME comment for more b=0 cases
dsolve: add a temporary FIXME comment for more b=0 cases

I hope its temporary anyway!

ChristinaZografou/sympy,madan96/sympy,Vishluck/sympy,garvitr/sympy,kaichogami/sympy,ga7g08/sympy,jerli/sympy,kevalds51/sympy,souravsingh/sympy,emon10005/sympy,debugger22/sympy,rahuldan/sympy,maniteja123/sympy,ChristinaZografou/sympy,Davidjohnwilson/sympy,bukzor/sympy,lindsayad/sympy,wanglongqi/sympy,aktech/sympy,pandeyadarsh/sympy,pandeyadarsh/sympy,wanglongqi/sympy,cswiercz/sympy,jbbskinny/sympy,yukoba/sympy,debugger22/sympy,cswiercz/sympy,jaimahajan1997/sympy,farhaanbukhsh/sympy,Designist/sympy,MechCoder/sympy,bukzor/sympy,souravsingh/sympy,abloomston/sympy,kevalds51/sympy,atreyv/sympy,drufat/sympy,drufat/sympy,Arafatk/sympy,kumarkrishna/sympy,lindsayad/sympy,souravsingh/sympy,toolforger/sympy,postvakje/sympy,abhiii5459/sympy,yashsharan/sympy,hargup/sympy,saurabhjn76/sympy,mcdaniel67/sympy,moble/sympy,postvakje/sympy,asm666/sympy,oliverlee/sympy,abloomston/sympy,shikil/sympy,chaffra/sympy,skidzo/sympy,kevalds51/sympy,sampadsaha5/sympy,kumarkrishna/sympy,MechCoder/sympy,kaushik94/sympy,ahhda/sympy,saurabhjn76/sympy,skidzo/sympy,hargup/sympy,atreyv/sympy,iamutkarshtiwari/sympy,Titan-C/sympy,sampadsaha5/sympy,mcdaniel67/sympy,Gadal/sympy,Curious72/sympy,mafiya69/sympy,Titan-C/sympy,oliverlee/sympy,drufat/sympy,kaichogami/sympy,hargup/sympy,wyom/sympy,atreyv/sympy,farhaanbukhsh/sympy,sahmed95/sympy,MechCoder/sympy,skidzo/sympy,Vishluck/sympy,mcdaniel67/sympy,pandeyadarsh/sympy,Arafatk/sympy,Shaswat27/sympy,yashsharan/sympy,VaibhavAgarwalVA/sympy,cswiercz/sympy,abhiii5459/sympy,garvitr/sympy,AkademieOlympia/sympy,emon10005/sympy,iamutkarshtiwari/sympy,yukoba/sympy,oliverlee/sympy,jbbskinny/sympy,abhiii5459/sympy,maniteja123/sympy,Gadal/sympy,iamutkarshtiwari/sympy,asm666/sympy,jerli/sympy,shikil/sympy,wanglongqi/sympy,ChristinaZografou/sympy,grevutiu-gabriel/sympy,rahuldan/sympy,yukoba/sympy,toolforger/sympy,Curious72/sympy,jbbskinny/sympy,bukzor/sympy,mafiya69/sympy,ga7g08/sympy,asm666/sympy,farhaanbukhsh/sympy,toolforger/sympy,moble/sympy,kaushik94/sympy,wyom/sympy,grevutiu-gabriel/sympy,AkademieOlympia/sympy,kumarkrishna/sympy,madan96/sympy,AkademieOlympia/sympy,ahhda/sympy,garvitr/sympy,Davidjohnwilson/sympy,Designist/sympy,atsao72/sympy,jerli/sympy,yashsharan/sympy,ahhda/sympy,Vishluck/sympy,mafiya69/sympy,abloomston/sympy,Shaswat27/sympy,lindsayad/sympy,jaimahajan1997/sympy,ga7g08/sympy,Arafatk/sympy,sahmed95/sympy,emon10005/sympy,chaffra/sympy,wyom/sympy,Titan-C/sympy,moble/sympy,rahuldan/sympy,maniteja123/sympy,saurabhjn76/sympy,Shaswat27/sympy,kaichogami/sympy,Davidjohnwilson/sympy,jaimahajan1997/sympy,Designist/sympy,chaffra/sympy,Gadal/sympy,debugger22/sympy,VaibhavAgarwalVA/sympy,aktech/sympy,postvakje/sympy,sampadsaha5/sympy,shikil/sympy,aktech/sympy,VaibhavAgarwalVA/sympy,madan96/sympy,grevutiu-gabriel/sympy,kaushik94/sympy,sahmed95/sympy,Curious72/sympy,atsao72/sympy,atsao72/sympy