RT-Thread/rt-thread: https://github.com/RT-Thread/rt-thread.git @ 2645aec2e3b5b805d697b2ec546faeb5157e8d81

Meco Man 2645aec2e3 删除没有用的预编译，在新版的IAR中此已经不需要了		5 lat temu
..
sys	6c7dd30532 add function settimeofday & stime	5 lat temu
SConscript	b3ab8a99e1 Signed-off-by: mysterywolf	5 lat temu
readme.md	d5f8830177 add newlib/dlib readme	5 lat temu
termios.h	54143409ca 增加#include <rtconfig.h> 防止开启termios功能后报错	5 lat temu
time.c	2645aec2e3 删除没有用的预编译，在新版的IAR中此已经不需要了	5 lat temu
unistd.c	96acad78ba 将posix_getline.h termios.h 头文件包含从<>改为""以防止路径出现分歧	5 lat temu

Attentions

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