unix/main: Refactor to put lexer constructors all in one place.
unix/main: Refactor to put lexer constructors all in one place.

The lexer can now raise an exception on construction so it must go within
an nlr handler block.

kerneltask/micropython,blazewicz/micropython,torwag/micropython,micropython/micropython-esp32,swegener/micropython,HenrikSolver/micropython,blazewicz/micropython,infinnovation/micropython,torwag/micropython,adafruit/circuitpython,pfalcon/micropython,alex-robbins/micropython,MrSurly/micropython,dmazzella/micropython,infinnovation/micropython,MrSurly/micropython-esp32,deshipu/micropython,kerneltask/micropython,TDAbboud/micropython,tobbad/micropython,pozetroninc/micropython,pfalcon/micropython,swegener/micropython,infinnovation/micropython,lowRISC/micropython,oopy/micropython,tobbad/micropython,hiway/micropython,TDAbboud/micropython,toolmacher/micropython,Peetz0r/micropython-esp32,PappaPeppar/micropython,selste/micropython,chrisdearman/micropython,Peetz0r/micropython-esp32,MrSurly/micropython,tralamazza/micropython,hiway/micropython,swegener/micropython,henriknelson/micropython,adafruit/micropython,toolmacher/micropython,kerneltask/micropython,chrisdearman/micropython,dmazzella/micropython,torwag/micropython,cwyark/micropython,AriZuu/micropython,toolmacher/micropython,Peetz0r/micropython-esp32,chrisdearman/micropython,deshipu/micropython,bvernoux/micropython,adafruit/circuitpython,selste/micropython,HenrikSolver/micropython,pozetroninc/micropython,AriZuu/micropython,trezor/micropython,oopy/micropython,pfalcon/micropython,PappaPeppar/micropython,alex-robbins/micropython,kerneltask/micropython,tobbad/micropython,selste/micropython,adafruit/circuitpython,kerneltask/micropython,lowRISC/micropython,pozetroninc/micropython,henriknelson/micropython,Peetz0r/micropython-esp32,bvernoux/micropython,trezor/micropython,alex-robbins/micropython,MrSurly/micropython-esp32,MrSurly/micropython,SHA2017-badge/micropython-esp32,bvernoux/micropython,trezor/micropython,infinnovation/micropython,adafruit/circuitpython,micropython/micropython-esp32,cwyark/micropython,toolmacher/micropython,Timmenem/micropython,selste/micropython,SHA2017-badge/micropython-esp32,blazewicz/micropython,pramasoul/micropython,hiway/micropython,AriZuu/micropython,cwyark/micropython,swegener/micropython,adafruit/circuitpython,PappaPeppar/micropython,bvernoux/micropython,adafruit/micropython,dmazzella/micropython,micropython/micropython-esp32,AriZuu/micropython,tobbad/micropython,MrSurly/micropython-esp32,ryannathans/micropython,adafruit/micropython,deshipu/micropython,TDAbboud/micropython,ryannathans/micropython,adafruit/micropython,lowRISC/micropython,lowRISC/micropython,trezor/micropython,ryannathans/micropython,alex-robbins/micropython,alex-robbins/micropython,cwyark/micropython,chrisdearman/micropython,hiway/micropython,adafruit/circuitpython,ryannathans/micropython,Timmenem/micropython,ryannathans/micropython,pramasoul/micropython,puuu/micropython,selste/micropython,deshipu/micropython,dmazzella/micropython,Timmenem/micropython,blazewicz/micropython,PappaPeppar/micropython,puuu/micropython,infinnovation/micropython,henriknelson/micropython,SHA2017-badge/micropython-esp32,pramasoul/micropython,MrSurly/micropython,micropython/micropython-esp32,henriknelson/micropython,MrSurly/micropython,Timmenem/micropython,puuu/micropython,deshipu/micropython,AriZuu/micropython,pramasoul/micropython,puuu/micropython,oopy/micropython,TDAbboud/micropython,chrisdearman/micropython,tralamazza/micropython,adafruit/micropython,tobbad/micropython,hiway/micropython,HenrikSolver/micropython,oopy/micropython,HenrikSolver/micropython,pozetroninc/micropython,tralamazza/micropython,pozetroninc/micropython,oopy/micropython,bvernoux/micropython,pramasoul/micropython,toolmacher/micropython,HenrikSolver/micropython,blazewicz/micropython,MrSurly/micropython-esp32,SHA2017-badge/micropython-esp32,tralamazza/micropython,Timmenem/micropython,torwag/micropython,cwyark/micropython,puuu/micropython,MrSurly/micropython-esp32,lowRISC/micropython,TDAbboud/micropython,PappaPeppar/micropython,SHA2017-badge/micropython-esp32,swegener/micropython,micropython/micropython-esp32,Peetz0r/micropython-esp32,torwag/micropython,trezor/micropython,henriknelson/micropython,pfalcon/micropython,pfalcon/micropython