unix: Enable extra compiler warnings.
unix: Enable extra compiler warnings.

To address issue #699.

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