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

fusl/src/stdio/fwscanf.c

Index: fusl/src/stdio/fwscanf.c
diff --git a/fusl/src/stdio/fwscanf.c b/fusl/src/stdio/fwscanf.c
new file mode 100644
index 0000000000000000000000000000000000000000..cb114b39f4bc9711b738aeac8f9ad8ec3ebc83db
--- /dev/null
+++ b/fusl/src/stdio/fwscanf.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <wchar.h>
+#include "libc.h"
+
+int fwscanf(FILE *restrict f, const wchar_t *restrict fmt, ...)
+{
+	int ret;
+	va_list ap;
+	va_start(ap, fmt);
+	ret = vfwscanf(f, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+weak_alias(fwscanf,__isoc99_fwscanf);