rt-thread/components/libc/compilers/common

Attentions

1. This folder is "common" for armlibc newlibc and dlib. It's not "common" for minilibc.

2. If you want to add new .c files, please do not forget to fix SConscript file too. eg:

if GetDepend('RT_USING_POSIX') == False:
        SrcRemove(src, ['unistd.c'])