RT-Thread/rt-thread: https://github.com/RT-Thread/rt-thread.git @ e63a45864728fc32d54063632598ccfbfd663c19

Bernard Xiong 83404b825b [libc] Does export time API if RTC component is not used.		10 lat temu
..
sys	eece1a7ac5 update armlibc/sys/errno.h: define EADDRNOTAVAIL	10 lat temu
SConscript	802c768475 [LIBC] Use RT_USING_LIBC instead of libs option for each compiler	11 lat temu
libc_syms.c	83404b825b [libc] Does export time API if RTC component is not used.	10 lat temu
mem_std.c	147901c2cb [Libc] Export more symbols for libc.	10 lat temu
stubs.c	87171f003c [LIBC] code cleanup	11 lat temu
unistd.h	7e981e3e26 [DFS] Fix the accept/shutdown issue in dfs_lwip.	10 lat temu