lib/libc: Add memchr. We already have strchr, but memchr is useful too.
lib/libc: Add memchr. We already have strchr, but memchr is useful too.

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