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

fusl/src/stdlib/strtol.c

+#include "stdio_impl.h"
+#include "intscan.h"
+#include "shgetc.h"
+#include <inttypes.h>
+#include <limits.h>
+#include <ctype.h>
+#include "libc.h"
+
+static unsigned long long strtox(const char *s, char **p, int base, unsigned long long lim)
+{
+        /* FIXME: use a helper function or macro to setup the FILE */
+        FILE f;
+        f.flags = 0;
+        f.buf = f.rpos = (void *)s;
+        if ((size_t)s > (size_t)-1/2)
+                f.rend = (void *)-1;
+        else
+                f.rend = (unsigned char *)s+(size_t)-1/2;
+        f.lock = -1;
+        shlim(&f, 0);
+        unsigned long long y = __intscan(&f, base, 1, lim);
+        if (p) {
+                size_t cnt = shcnt(&f);
+                *p = (char *)s + cnt;
+        }
+        return y;
+}
+
+unsigned long long strtoull(const char *restrict s, char **restrict p, int base)
+{
+        return strtox(s, p, base, ULLONG_MAX);
+}
+
+long long strtoll(const char *restrict s, char **restrict p, int base)
+{
+        return strtox(s, p, base, LLONG_MIN);
+}
+
+unsigned long strtoul(const char *restrict s, char **restrict p, int base)
+{
+        return strtox(s, p, base, ULONG_MAX);
+}
+
+long strtol(const char *restrict s, char **restrict p, int base)
+{
+        return strtox(s, p, base, 0UL+LONG_MIN);
+}
+
+intmax_t strtoimax(const char *restrict s, char **restrict p, int base)
+{
+        return strtoll(s, p, base);
+}
+
+uintmax_t strtoumax(const char *restrict s, char **restrict p, int base)
+{
+        return strtoull(s, p, base);
+}
+
+weak_alias(strtol, __strtol_internal);
+weak_alias(strtoul, __strtoul_internal);
+weak_alias(strtoll, __strtoll_internal);
+weak_alias(strtoull, __strtoull_internal);
+weak_alias(strtoimax, __strtoimax_internal);
+weak_alias(strtoumax, __strtoumax_internal);