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

fusl/src/ctype/iswctype.c

+#include <wctype.h>
+#include <string.h>
+#include "libc.h"
+
+#define WCTYPE_ALNUM  1
+#define WCTYPE_ALPHA  2
+#define WCTYPE_BLANK  3
+#define WCTYPE_CNTRL  4
+#define WCTYPE_DIGIT  5
+#define WCTYPE_GRAPH  6
+#define WCTYPE_LOWER  7
+#define WCTYPE_PRINT  8
+#define WCTYPE_PUNCT  9
+#define WCTYPE_SPACE  10
+#define WCTYPE_UPPER  11
+#define WCTYPE_XDIGIT 12
+
+int iswctype(wint_t wc, wctype_t type)
+{
+        switch (type) {
+        case WCTYPE_ALNUM:
+                return iswalnum(wc);
+        case WCTYPE_ALPHA:
+                return iswalpha(wc);
+        case WCTYPE_BLANK:
+                return iswblank(wc);
+        case WCTYPE_CNTRL:
+                return iswcntrl(wc);
+        case WCTYPE_DIGIT:
+                return iswdigit(wc);
+        case WCTYPE_GRAPH:
+                return iswgraph(wc);
+        case WCTYPE_LOWER:
+                return iswlower(wc);
+        case WCTYPE_PRINT:
+                return iswprint(wc);
+        case WCTYPE_PUNCT:
+                return iswpunct(wc);
+        case WCTYPE_SPACE:
+                return iswspace(wc);
+        case WCTYPE_UPPER:
+                return iswupper(wc);
+        case WCTYPE_XDIGIT:
+                return iswxdigit(wc);
+        }
+        return 0;
+}
+
+wctype_t wctype(const char *s)
+{
+        int i;
+        const char *p;
+        /* order must match! */
+        static const char names[] =
+                "alnum\0" "alpha\0" "blank\0"
+                "cntrl\0" "digit\0" "graph\0"
+                "lower\0" "print\0" "punct\0"
+                "space\0" "upper\0" "xdigit";
+        for (i=1, p=names; *p; i++, p+=6)
+                if (*s == *p && !strcmp(s, p))
+                        return i;
+        return 0;
+}
+
+int __iswctype_l(wint_t c, wctype_t t, locale_t l)
+{
+        return iswctype(c, t);
+}
+
+wctype_t __wctype_l(const char *s, locale_t l)
+{
+        return wctype(s);
+}
+
+weak_alias(__iswctype_l, iswctype_l);
+weak_alias(__wctype_l, wctype_l);