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

fusl/src/locale/strxfrm.c

+#include <string.h>
+#include <locale.h>
+#include "locale_impl.h"
+#include "libc.h"
+
+/* collate only by code points */
+size_t __strxfrm_l(char *restrict dest, const char *restrict src, size_t n, locale_t loc)
+{
+        size_t l = strlen(src);
+        if (n > l) strcpy(dest, src);
+        return l;
+}
+
+size_t strxfrm(char *restrict dest, const char *restrict src, size_t n)
+{
+        return __strxfrm_l(dest, src, n, CURRENT_LOCALE);
+}
+
+weak_alias(__strxfrm_l, strxfrm_l);