py: Fix bug in compiler for empty class bases.
py: Fix bug in compiler for empty class bases.

Eg class A(): pass would fail an assertion.

KISSMonX/micropython,ChuckM/micropython,ryannathans/micropython,pfalcon/micropython,MrSurly/micropython,hiway/micropython,tralamazza/micropython,adamkh/micropython,dhylands/micropython,praemdonck/micropython,alex-robbins/micropython,chrisdearman/micropython,vriera/micropython,henriknelson/micropython,adafruit/micropython,kostyll/micropython,adafruit/circuitpython,infinnovation/micropython,jimkmc/micropython,selste/micropython,mhoffma/micropython,AriZuu/micropython,selste/micropython,toolmacher/micropython,SungEun-Steve-Kim/test-mp,dxxb/micropython,HenrikSolver/micropython,omtinez/micropython,ganshun666/micropython,selste/micropython,adafruit/circuitpython,Timmenem/micropython,turbinenreiter/micropython,kostyll/micropython,hiway/micropython,firstval/micropython,jmarcelino/pycom-micropython,Vogtinator/micropython,emfcamp/micropython,cnoviello/micropython,bvernoux/micropython,MrSurly/micropython,redbear/micropython,AriZuu/micropython,xuxiaoxin/micropython,pramasoul/micropython,jlillest/micropython,rubencabrera/micropython,MrSurly/micropython,xhat/micropython,kerneltask/micropython,noahwilliamsson/micropython,micropython/micropython-esp32,xyb/micropython,jlillest/micropython,hiway/micropython,alex-robbins/micropython,henriknelson/micropython,redbear/micropython,SHA2017-badge/micropython-esp32,torwag/micropython,dinau/micropython,misterdanb/micropython,jimkmc/micropython,SungEun-Steve-Kim/test-mp,turbinenreiter/micropython,adafruit/micropython,alex-march/micropython,ceramos/micropython,TDAbboud/micropython,cloudformdesign/micropython,TDAbboud/micropython,MrSurly/micropython-esp32,Peetz0r/micropython-esp32,PappaPeppar/micropython,EcmaXp/micropython,puuu/micropython,SHA2017-badge/micropython-esp32,tobbad/micropython,EcmaXp/micropython,xhat/micropython,dxxb/micropython,stonegithubs/micropython,firstval/micropython,mgyenik/micropython,ganshun666/micropython,ganshun666/micropython,kostyll/micropython,pozetroninc/micropython,matthewelse/micropython,pramasoul/micropython,adafruit/micropython,jlillest/micropython,cwyark/micropython,xuxiaoxin/micropython,hosaka/micropython,galenhz/micropython,alex-robbins/micropython,martinribelotta/micropython,dxxb/micropython,xyb/micropython,orionrobots/micropython,ceramos/micropython,martinribelotta/micropython,jimkmc/micropython,stonegithubs/micropython,slzatz/micropython,mpalomer/micropython,ChuckM/micropython,ryannathans/micropython,PappaPeppar/micropython,adafruit/micropython,kerneltask/micropython,danicampora/micropython,skybird6672/micropython,dinau/micropython,vriera/micropython,cnoviello/micropython,supergis/micropython,heisewangluo/micropython,MrSurly/micropython-esp32,neilh10/micropython,alex-robbins/micropython,noahchense/micropython,omtinez/micropython,adamkh/micropython,xyb/micropython,cnoviello/micropython,lbattraw/micropython,Timmenem/micropython,noahwilliamsson/micropython,HenrikSolver/micropython,slzatz/micropython,kerneltask/micropython,firstval/micropython,warner83/micropython,infinnovation/micropython,turbinenreiter/micropython,redbear/micropython,blazewicz/micropython,drrk/micropython,micropython/micropython-esp32,orionrobots/micropython,vitiral/micropython,ruffy91/micropython,HenrikSolver/micropython,tuc-osg/micropython,puuu/micropython,infinnovation/micropython,ruffy91/micropython,blmorris/micropython,toolmacher/micropython,SHA2017-badge/micropython-esp32,methoxid/micropystat,lowRISC/micropython,selste/micropython,SungEun-Steve-Kim/test-mp,xuxiaoxin/micropython,ernesto-g/micropython,emfcamp/micropython,hosaka/micropython,neilh10/micropython,jimkmc/micropython,Vogtinator/micropython,neilh10/micropython,tralamazza/micropython,ceramos/micropython,trezor/micropython,PappaPeppar/micropython,feilongfl/micropython,skybird6672/micropython,utopiaprince/micropython,pramasoul/micropython,mhoffma/micropython,aitjcize/micropython,chrisdearman/micropython,redbear/micropython,martinribelotta/micropython,galenhz/micropython,adamkh/micropython,henriknelson/micropython,rubencabrera/micropython,paul-xxx/micropython,MrSurly/micropython-esp32,trezor/micropython,jlillest/micropython,tdautc19841202/micropython,Vogtinator/micropython,xhat/micropython,SHA2017-badge/micropython-esp32,dhylands/micropython,matthewelse/micropython,Vogtinator/micropython,chrisdearman/micropython,ceramos/micropython,HenrikSolver/micropython,pozetroninc/micropython,turbinenreiter/micropython,vitiral/micropython,torwag/micropython,matthewelse/micropython,micropython/micropython-esp32,swegener/micropython,torwag/micropython,hosaka/micropython,tdautc19841202/micropython,MrSurly/micropython,KISSMonX/micropython,vitiral/micropython,mhoffma/micropython,mianos/micropython,paul-xxx/micropython,praemdonck/micropython,adafruit/circuitpython,tobbad/micropython,trezor/micropython,paul-xxx/micropython,cwyark/micropython,EcmaXp/micropython,paul-xxx/micropython,alex-march/micropython,toolmacher/micropython,cloudformdesign/micropython,ahotam/micropython,emfcamp/micropython,oopy/micropython,xhat/micropython,xuxiaoxin/micropython,mpalomer/micropython,AriZuu/micropython,ChuckM/micropython,ahotam/micropython,praemdonck/micropython,cwyark/micropython,lowRISC/micropython,ruffy91/micropython,HenrikSolver/micropython,misterdanb/micropython,lowRISC/micropython,danicampora/micropython,ruffy91/micropython,mianos/micropython,blmorris/micropython,MrSurly/micropython,suda/micropython,drrk/micropython,alex-robbins/micropython,kostyll/micropython,slzatz/micropython,PappaPeppar/micropython,dinau/micropython,ericsnowcurrently/micropython,blazewicz/micropython,jmarcelino/pycom-micropython,vitiral/micropython,mgyenik/micropython,orionrobots/micropython,supergis/micropython,Vogtinator/micropython,pozetroninc/micropython,lbattraw/micropython,feilongfl/micropython,praemdonck/micropython,pfalcon/micropython,cwyark/micropython,adafruit/micropython,praemdonck/micropython,mianos/micropython,heisewangluo/micropython,dhylands/micropython,dhylands/micropython,jmarcelino/pycom-micropython,warner83/micropython,emfcamp/micropython,martinribelotta/micropython,EcmaXp/micropython,torwag/micropython,jmarcelino/pycom-micropython,pramasoul/micropython,noahchense/micropython,swegener/micropython,micropython/micropython-esp32,tobbad/micropython,alex-march/micropython,henriknelson/micropython,Timmenem/micropython,warner83/micropython,danicampora/micropython,skybird6672/micropython,ericsnowcurrently/micropython,noahwilliamsson/micropython,tuc-osg/micropython,drrk/micropython,jimkmc/micropython,PappaPeppar/micropython,trezor/micropython,hiway/micropython,swegener/micropython,aethaniel/micropython,xuxiaoxin/micropython,blazewicz/micropython,mianos/micropython,mpalomer/micropython,ryannathans/micropython,TDAbboud/micropython,lbattraw/micropython,oopy/micropython,tralamazza/micropython,deshipu/micropython,tdautc19841202/micropython,AriZuu/micropython,heisewangluo/micropython,skybird6672/micropython,utopiaprince/micropython,oopy/micropython,slzatz/micropython,xyb/micropython,methoxid/micropystat,alex-march/micropython,blmorris/micropython,noahwilliamsson/micropython,bvernoux/micropython,ganshun666/micropython,danicampora/micropython,bvernoux/micropython,alex-march/micropython,dhylands/micropython,TDAbboud/micropython,bvernoux/micropython,ChuckM/micropython,ernesto-g/micropython,omtinez/micropython,mgyenik/micropython,hiway/micropython,dxxb/micropython,methoxid/micropystat,galenhz/micropython,puuu/micropython,mpalomer/micropython,swegener/micropython,dmazzella/micropython,rubencabrera/micropython,SHA2017-badge/micropython-esp32,galenhz/micropython,utopiaprince/micropython,redbear/micropython,ceramos/micropython,ryannathans/micropython,KISSMonX/micropython,supergis/micropython,adafruit/circuitpython,aethaniel/micropython,dmazzella/micropython,utopiaprince/micropython,methoxid/micropystat,ChuckM/micropython,aethaniel/micropython,dinau/micropython,jmarcelino/pycom-micropython,noahchense/micropython,tdautc19841202/micropython,pramasoul/micropython,blmorris/micropython,drrk/micropython,blazewicz/micropython,stonegithubs/micropython,heisewangluo/micropython,neilh10/micropython,AriZuu/micropython,ernesto-g/micropython,pfalcon/micropython,stonegithubs/micropython,pozetroninc/micropython,rubencabrera/micropython,MrSurly/micropython-esp32,aethaniel/micropython,utopiaprince/micropython,infinnovation/micropython,ericsnowcurrently/micropython,hosaka/micropython,suda/micropython,orionrobots/micropython,ganshun666/micropython,SungEun-Steve-Kim/test-mp,dmazzella/micropython,ernesto-g/micropython,Peetz0r/micropython-esp32,danicampora/micropython,matthewelse/micropython,cnoviello/micropython,misterdanb/micropython,supergis/micropython,Timmenem/micropython,KISSMonX/micropython,cloudformdesign/micropython,aitjcize/micropython,deshipu/micropython,aitjcize/micropython,ericsnowcurrently/micropython,tuc-osg/micropython,Peetz0r/micropython-esp32,noahwilliamsson/micropython,tobbad/micropython,vriera/micropython,SungEun-Steve-Kim/test-mp,noahchense/micropython,deshipu/micropython,lbattraw/micropython,xyb/micropython,pozetroninc/micropython,vriera/micropython,cloudformdesign/micropython,tdautc19841202/micropython,warner83/micropython,bvernoux/micropython,cloudformdesign/micropython,cwyark/micropython,chrisdearman/micropython,aethaniel/micropython,misterdanb/micropython,aitjcize/micropython,kostyll/micropython,blazewicz/micropython,firstval/micropython,rubencabrera/micropython,infinnovation/micropython,Peetz0r/micropython-esp32,feilongfl/micropython,suda/micropython,torwag/micropython,adafruit/circuitpython,blmorris/micropython,matthewelse/micropython,warner83/micropython,oopy/micropython,pfalcon/micropython,ahotam/micropython,stonegithubs/micropython,selste/micropython,feilongfl/micropython,mgyenik/micropython,vriera/micropython,ruffy91/micropython,tuc-osg/micropython,puuu/micropython,dinau/micropython,paul-xxx/micropython,omtinez/micropython,ernesto-g/micropython,galenhz/micropython,slzatz/micropython,tralamazza/micropython,trezor/micropython,supergis/micropython,adafruit/circuitpython,tobbad/micropython,martinribelotta/micropython,matthewelse/micropython,heisewangluo/micropython,suda/micropython,lowRISC/micropython,methoxid/micropystat,adamkh/micropython,Peetz0r/micropython-esp32,misterdanb/micropython,KISSMonX/micropython,mhoffma/micropython,deshipu/micropython,oopy/micropython,pfalcon/micropython,tuc-osg/micropython,henriknelson/micropython,dxxb/micropython,MrSurly/micropython-esp32,neilh10/micropython,TDAbboud/micropython,ahotam/micropython,EcmaXp/micropython,feilongfl/micropython,adamkh/micropython,lbattraw/micropython,toolmacher/micropython,xhat/micropython,orionrobots/micropython,ericsnowcurrently/micropython,hosaka/micropython,ryannathans/micropython,vitiral/micropython,kerneltask/micropython,skybird6672/micropython,omtinez/micropython,mhoffma/micropython,suda/micropython,puuu/micropython,swegener/micropython,mpalomer/micropython,kerneltask/micropython,lowRISC/micropython,micropython/micropython-esp32,noahchense/micropython,deshipu/micropython,firstval/micropython,cnoviello/micropython,mianos/micropython,ahotam/micropython,Timmenem/micropython,emfcamp/micropython,dmazzella/micropython,turbinenreiter/micropython,drrk/micropython,toolmacher/micropython,chrisdearman/micropython,mgyenik/micropython,jlillest/micropython