windows: Enable multi-processor compilation for msvc
windows: Enable multi-processor compilation for msvc

This will launch about as many compiler instances as there are logical
processors on a machine, and as such significantly speeds up compilation.

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