core: add ARRAY_SIZE macro
core: add ARRAY_SIZE macro

aeneby/RIOT,aeneby/RIOT,OlegHahm/RIOT,toonst/RIOT,x3ro/RIOT,toonst/RIOT,authmillenon/RIOT,authmillenon/RIOT,smlng/RIOT,basilfx/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,smlng/RIOT,cladmi/RIOT,OlegHahm/RIOT,authmillenon/RIOT,ant9000/RIOT,OlegHahm/RIOT,aeneby/RIOT,josephnoir/RIOT,OTAkeys/RIOT,mtausig/RIOT,rfuentess/RIOT,basilfx/RIOT,mtausig/RIOT,aeneby/RIOT,smlng/RIOT,rfuentess/RIOT,josephnoir/RIOT,toonst/RIOT,yogo1212/RIOT,kYc0o/RIOT,cladmi/RIOT,miri64/RIOT,miri64/RIOT,basilfx/RIOT,yogo1212/RIOT,smlng/RIOT,basilfx/RIOT,ant9000/RIOT,josephnoir/RIOT,OlegHahm/RIOT,kYc0o/RIOT,miri64/RIOT,basilfx/RIOT,rfuentess/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,miri64/RIOT,mtausig/RIOT,miri64/RIOT,mtausig/RIOT,yogo1212/RIOT,toonst/RIOT,x3ro/RIOT,kaspar030/RIOT,rfuentess/RIOT,OTAkeys/RIOT,jasonatran/RIOT,ant9000/RIOT,jasonatran/RIOT,jasonatran/RIOT,OlegHahm/RIOT,cladmi/RIOT,josephnoir/RIOT,kYc0o/RIOT,smlng/RIOT,x3ro/RIOT,mtausig/RIOT,authmillenon/RIOT,cladmi/RIOT,RIOT-OS/RIOT,OTAkeys/RIOT,cladmi/RIOT,kaspar030/RIOT,OTAkeys/RIOT,toonst/RIOT,kaspar030/RIOT,yogo1212/RIOT,yogo1212/RIOT,josephnoir/RIOT,ant9000/RIOT,aeneby/RIOT,OTAkeys/RIOT,kYc0o/RIOT,authmillenon/RIOT,x3ro/RIOT,x3ro/RIOT,ant9000/RIOT,rfuentess/RIOT,kaspar030/RIOT,authmillenon/RIOT