ref: c1ecdce3a2c041d6317f02f56955ceaef8c2747f dir: /sys/src/cmd/unix/drawterm/libc/runestrcat.c/
#include <u.h> #include <libc.h> Rune* runestrcat(Rune *s1, Rune *s2) { runestrcpy(runestrchr(s1, 0), s2); return s1; }