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

fusl/src/string/strlcpy.c

Index: fusl/src/string/strlcpy.c
diff --git a/fusl/src/string/strlcpy.c b/fusl/src/string/strlcpy.c
new file mode 100644
index 0000000000000000000000000000000000000000..193d724130eca36d7939819e2d7ec94889dca3ef
--- /dev/null
+++ b/fusl/src/string/strlcpy.c
@@ -0,0 +1,32 @@
+#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);
+}