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

fusl/include/locale.h

+#ifndef _LOCALE_H
+#define _LOCALE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#ifdef __cplusplus
+#define NULL 0L
+#else
+#define NULL ((void*)0)
+#endif
+
+#define LC_CTYPE    0
+#define LC_NUMERIC  1
+#define LC_TIME     2
+#define LC_COLLATE  3
+#define LC_MONETARY 4
+#define LC_MESSAGES 5
+#define LC_ALL      6
+
+struct lconv {
+        char *decimal_point;
+        char *thousands_sep;
+        char *grouping;
+
+        char *int_curr_symbol;
+        char *currency_symbol;
+        char *mon_decimal_point;
+        char *mon_thousands_sep;
+        char *mon_grouping;
+        char *positive_sign;
+        char *negative_sign;
+        char int_frac_digits;
+        char frac_digits;
+        char p_cs_precedes;
+        char p_sep_by_space;
+        char n_cs_precedes;
+        char n_sep_by_space;
+        char p_sign_posn;
+        char n_sign_posn;
+        char int_p_cs_precedes;
+        char int_p_sep_by_space;
+        char int_n_cs_precedes;
+        char int_n_sep_by_space;
+        char int_p_sign_posn;
+        char int_n_sign_posn;
+};
+
+
+char *setlocale (int, const char *);
+struct lconv *localeconv(void);
+
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+
+#define __NEED_locale_t
+
+#include <bits/alltypes.h>
+
+#define LC_GLOBAL_LOCALE ((locale_t)-1)
+
+#define LC_CTYPE_MASK    (1<<LC_CTYPE)
+#define LC_NUMERIC_MASK  (1<<LC_NUMERIC)
+#define LC_TIME_MASK     (1<<LC_TIME)
+#define LC_COLLATE_MASK  (1<<LC_COLLATE)
+#define LC_MONETARY_MASK (1<<LC_MONETARY)
+#define LC_MESSAGES_MASK (1<<LC_MESSAGES)
+#define LC_ALL_MASK      0x7fffffff
+
+locale_t duplocale(locale_t);
+void freelocale(locale_t);
+locale_t newlocale(int, const char *, locale_t);
+locale_t uselocale(locale_t);
+
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif