Add a "fork" of musl as //fusl.

fusl/src/string/strlcpy.c

+#define _BSD_SOURCE
+#include <string.h>
+#include <stdint.h>
+#include <limits.h>
+#include "libc.h"
+
+#define ALIGN (sizeof(size_t)-1)
+#define ONES ((size_t)-1/UCHAR_MAX)
+#define HIGHS (ONES * (UCHAR_MAX/2+1))
+#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
+
+size_t strlcpy(char *d, const char *s, size_t n)
+{
+        char *d0 = d;
+        size_t *wd;
+        const size_t *ws;
+
+        if (!n--) goto finish;
+        if (((uintptr_t)s & ALIGN) == ((uintptr_t)d & ALIGN)) {
+                for (; ((uintptr_t)s & ALIGN) && n && (*d=*s); n--, s++, d++);
+                if (n && *s) {
+                        wd=(void *)d; ws=(const void *)s;
+                        for (; n>=sizeof(size_t) && !HASZERO(*ws);
+                               n-=sizeof(size_t), ws++, wd++) *wd = *ws;
+                        d=(void *)wd; s=(const void *)ws;
+                }
+        }
+        for (; n && (*d=*s); n--, s++, d++);
+        *d = 0;
+finish:
+        return d-d0 + strlen(s);
+}