py: Eliminate 'op' variable in VM dispatch loop.
py: Eliminate 'op' variable in VM dispatch loop.

Remembering the last op is rarely needed, and when it is, can simply use
*save_ip.

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