In HardwareSerial, don't use int for buffer indices#1863

cmaglie merged 1 commit intoarduino:ide-1.5.xarduino/Arduino:ide-1.5.xfrom

matthijskooijman:ide-1.5.x-serial-intmatthijskooijman/Arduino:ide-1.5.x-serial-intCopy head branch name to clipboard