py/modthread: Add exit() function.
py/modthread: Add exit() function.

Simply raises the SystemExit exception.

Timmenem/micropython,alex-robbins/micropython,alex-march/micropython,dxxb/micropython,blazewicz/micropython,mhoffma/micropython,chrisdearman/micropython,pfalcon/micropython,HenrikSolver/micropython,Peetz0r/micropython-esp32,redbear/micropython,adafruit/circuitpython,Peetz0r/micropython-esp32,lowRISC/micropython,blazewicz/micropython,swegener/micropython,Timmenem/micropython,kerneltask/micropython,kerneltask/micropython,ganshun666/micropython,turbinenreiter/micropython,jmarcelino/pycom-micropython,blazewicz/micropython,Peetz0r/micropython-esp32,ryannathans/micropython,HenrikSolver/micropython,oopy/micropython,toolmacher/micropython,hosaka/micropython,pramasoul/micropython,ganshun666/micropython,deshipu/micropython,puuu/micropython,pozetroninc/micropython,micropython/micropython-esp32,TDAbboud/micropython,hiway/micropython,mhoffma/micropython,selste/micropython,adafruit/micropython,pozetroninc/micropython,dxxb/micropython,redbear/micropython,matthewelse/micropython,tuc-osg/micropython,cwyark/micropython,deshipu/micropython,PappaPeppar/micropython,AriZuu/micropython,TDAbboud/micropython,tralamazza/micropython,SHA2017-badge/micropython-esp32,adafruit/circuitpython,micropython/micropython-esp32,tobbad/micropython,tralamazza/micropython,MrSurly/micropython,ryannathans/micropython,HenrikSolver/micropython,oopy/micropython,turbinenreiter/micropython,ryannathans/micropython,tuc-osg/micropython,MrSurly/micropython,MrSurly/micropython-esp32,MrSurly/micropython,hiway/micropython,tobbad/micropython,trezor/micropython,HenrikSolver/micropython,alex-robbins/micropython,emfcamp/micropython,adafruit/circuitpython,dmazzella/micropython,PappaPeppar/micropython,puuu/micropython,SHA2017-badge/micropython-esp32,AriZuu/micropython,tobbad/micropython,emfcamp/micropython,bvernoux/micropython,tralamazza/micropython,puuu/micropython,PappaPeppar/micropython,mhoffma/micropython,hosaka/micropython,HenrikSolver/micropython,blazewicz/micropython,henriknelson/micropython,ryannathans/micropython,infinnovation/micropython,pramasoul/micropython,blazewicz/micropython,alex-march/micropython,turbinenreiter/micropython,kerneltask/micropython,AriZuu/micropython,ganshun666/micropython,bvernoux/micropython,AriZuu/micropython,lowRISC/micropython,mhoffma/micropython,toolmacher/micropython,henriknelson/micropython,AriZuu/micropython,deshipu/micropython,alex-robbins/micropython,pozetroninc/micropython,pozetroninc/micropython,redbear/micropython,henriknelson/micropython,deshipu/micropython,chrisdearman/micropython,pfalcon/micropython,pfalcon/micropython,kerneltask/micropython,puuu/micropython,torwag/micropython,trezor/micropython,tuc-osg/micropython,SHA2017-badge/micropython-esp32,kerneltask/micropython,ryannathans/micropython,jmarcelino/pycom-micropython,torwag/micropython,dmazzella/micropython,adafruit/circuitpython,adafruit/micropython,pozetroninc/micropython,cwyark/micropython,alex-march/micropython,pramasoul/micropython,adafruit/micropython,emfcamp/micropython,lowRISC/micropython,jmarcelino/pycom-micropython,MrSurly/micropython,cwyark/micropython,lowRISC/micropython,tobbad/micropython,torwag/micropython,selste/micropython,pramasoul/micropython,Timmenem/micropython,Timmenem/micropython,swegener/micropython,Timmenem/micropython,infinnovation/micropython,TDAbboud/micropython,redbear/micropython,pramasoul/micropython,adafruit/micropython,PappaPeppar/micropython,hiway/micropython,alex-robbins/micropython,tuc-osg/micropython,deshipu/micropython,henriknelson/micropython,swegener/micropython,Peetz0r/micropython-esp32,bvernoux/micropython,bvernoux/micropython,adafruit/micropython,bvernoux/micropython,pfalcon/micropython,SHA2017-badge/micropython-esp32,mhoffma/micropython,emfcamp/micropython,henriknelson/micropython,jmarcelino/pycom-micropython,ganshun666/micropython,MrSurly/micropython-esp32,dxxb/micropython,swegener/micropython,turbinenreiter/micropython,emfcamp/micropython,micropython/micropython-esp32,Peetz0r/micropython-esp32,infinnovation/micropython,matthewelse/micropython,selste/micropython,trezor/micropython,pfalcon/micropython,MrSurly/micropython-esp32,puuu/micropython,redbear/micropython,micropython/micropython-esp32,hosaka/micropython,torwag/micropython,TDAbboud/micropython,alex-march/micropython,adafruit/circuitpython,torwag/micropython,matthewelse/micropython,MrSurly/micropython,infinnovation/micropython,micropython/micropython-esp32,tralamazza/micropython,oopy/micropython,alex-march/micropython,swegener/micropython,dmazzella/micropython,adafruit/circuitpython,infinnovation/micropython,toolmacher/micropython,alex-robbins/micropython,trezor/micropython,jmarcelino/pycom-micropython,matthewelse/micropython,chrisdearman/micropython,lowRISC/micropython,toolmacher/micropython,chrisdearman/micropython,matthewelse/micropython,matthewelse/micropython,dmazzella/micropython,hiway/micropython,cwyark/micropython,selste/micropython,selste/micropython,dxxb/micropython,hiway/micropython,oopy/micropython,hosaka/micropython,dxxb/micropython,MrSurly/micropython-esp32,PappaPeppar/micropython,tuc-osg/micropython,tobbad/micropython,MrSurly/micropython-esp32,turbinenreiter/micropython,SHA2017-badge/micropython-esp32,ganshun666/micropython,TDAbboud/micropython,chrisdearman/micropython,toolmacher/micropython,hosaka/micropython,oopy/micropython,cwyark/micropython,trezor/micropython