RT-Thread/rt-thread: https://github.com/RT-Thread/rt-thread.git @ a00a463248bc66cff04e098c2440e90bf7ea273e

Meco Man 8fee8d2c8c remove const in set_timeval		4 lat temu
..
none-gcc	cb7fa8fcea implement pid_t gettid(void)	4 lat temu
sys	1a55702ccb 修复DST_NONE 等宏定义位置放错导致报错的问题	4 lat temu
SConscript	ae66d82624 update sconscript	4 lat temu
dirent.h	f9ba41f4c2 更改libc目录为common 以及 none-gcc	4 lat temu
readme.md	f9ba41f4c2 更改libc目录为common 以及 none-gcc	4 lat temu
stdlib.c	3c05a4e719 [compoenets] auto & manual formatted	4 lat temu
termios.h	3c05a4e719 [compoenets] auto & manual formatted	4 lat temu
time.c	8fee8d2c8c remove const in set_timeval	4 lat temu
unistd.c	19347ed454 [libc][unistd] 完善isatty()	4 lat temu

Attentions

This folder is "common" for all toolchains.
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'])
```