libc: add __wcsncpy_chk() to support python 3.10

Signed-off-by: Waldemar Kozaczuk <jwkozaczuk@gmail.com>

Author: wkozaczuk

Makefile

@@ -1796,6 +1796,7 @@ musl += string/wcsncasecmp_l.o
 musl += string/wcsncat.o
 musl += string/wcsncmp.o
 musl += string/wcsncpy.o
+libc += string/__wcsncpy_chk.o
 musl += string/wcsnlen.o
 musl += string/wcspbrk.o
 musl += string/wcsrchr.o

libc/string/__wcsncpy_chk.c

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2022 Waldemar Kozaczuk
+ *
+ * This work is open source software, licensed under the terms of the
+ * BSD license as described in the LICENSE file in the top-level directory.
+ */
+
+#include <wchar.h>
+#include <assert.h>
+
+wchar_t *__wcsncpy_chk(wchar_t * dest, const wchar_t * src, size_t n, size_t destlen)
+{
+    assert(wcslen(src) + sizeof(L'\0') <= destlen);
+    return wcsncpy(dest, src, n);
+}