add all missing wchar functions except floating point parsers

these are mostly untested and adapted directly from corresponding byte
string functions and similar.

include/wchar.h

@@ -11,6 +11,11 @@ extern "C" {
 #define __NEED_wchar_t
 #define __NEED_wint_t
 
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+#define __NEED_locale_t
+#endif
+
 #if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
 #define __NEED_wctype_t
 #endif
@@ -132,6 +137,16 @@ size_t wcsftime (wchar_t *, size_t, const wchar_t *, const struct tm *);
 FILE *open_wmemstream(wchar_t **, size_t *);
 size_t mbsnrtowcs(wchar_t *, const char **, size_t, size_t, mbstate_t *);
 size_t wcsnrtombs(char *, const wchar_t **, size_t, size_t, mbstate_t *);
+wchar_t *wcsdup(const wchar_t *);
+size_t wcsnlen (const wchar_t *, size_t);
+wchar_t *wcpcpy (wchar_t *, const wchar_t *);
+wchar_t *wcpncpy (wchar_t *, const wchar_t *, size_t);
+int wcscasecmp(const wchar_t *, const wchar_t *);
+int wcscasecmp_l(const wchar_t *, const wchar_t *, locale_t);
+int wcsncasecmp(const wchar_t *, const wchar_t *, size_t);
+int wcsncasecmp_l(const wchar_t *, const wchar_t *, size_t, locale_t);
+int wcscoll_l(const wchar_t *, const wchar_t *, locale_t);
+size_t wcsxfrm_l(wchar_t *, const wchar_t *, size_t n, locale_t);
 #endif
 
 #if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)

src/locale/wcscoll_l.c

+#include <wchar.h>
+
+int wcscoll_l(const wchar_t *l, const wchar_t *r, locale_t locale)
+{
+	return wcscoll(l, r);
+}

src/locale/wcsxfrm_l.c

+#include <wchar.h>
+
+size_t wcsxfrm_l(wchar_t *dest, const wchar_t *src, size_t n, locale_t locale)
+{
+	return wcsxfrm(dest, src, n);
+}

src/string/wcpcpy.c

+#include <wchar.h>
+
+wchar_t *wcpcpy(wchar_t *d, const wchar_t *s)
+{
+	return wcscpy(d, s) + wcslen(s);
+}

src/string/wcpncpy.c

+#include <wchar.h>
+
+wchar_t *wcpncpy(wchar_t *d, const wchar_t *s, size_t n)
+{
+	return wcsncpy(d, s, n) + wcsnlen(s, n);
+}

src/string/wcscasecmp.c

+#include <wchar.h>
+#include <wctype.h>
+
+int wcscasecmp(const wchar_t *l, const wchar_t *r)
+{
+	return wcsncasecmp(l, r, -1);
+}

src/string/wcscasecmp_l.c

+#include <wchar.h>
+
+int wcscasecmp_l(const wchar_t *l, const wchar_t *r, locale_t locale)
+{
+	return wcscasecmp(l, r);
+}

src/string/wcsdup.c

+#include <stdlib.h>
+#include <wchar.h>
+#include "libc.h"
+
+wchar_t *wcsdup(const wchar_t *s)
+{
+	size_t l = wcslen(s);
+	wchar_t *d = malloc((l+1)*sizeof(wchar_t));
+	if (!d) return NULL;
+	return wmemcpy(d, s, l+1);
+}

src/string/wcsncasecmp.c

+#include <wchar.h>
+#include <wctype.h>
+
+int wcsncasecmp(const wchar_t *l, const wchar_t *r, size_t n)
+{
+	if (!n--) return 0;
+	for (; *l && *r && n && (*l == *r || towlower(*l) == towlower(*r)); l++, r++, n--);
+	return towlower(*l) - towlower(*r);
+}

src/string/wcsncasecmp_l.c

+#include <wchar.h>
+
+int wcsncasecmp_l(const wchar_t *l, const wchar_t *r, size_t n, locale_t locale)
+{
+	return wcsncasecmp(l, r, n);
+}

src/string/wcsnlen.c

+#include <wchar.h>
+
+size_t wcsnlen(const wchar_t *s, size_t n)
+{
+	const wchar_t *z = wmemchr(s, 0, n);
+	if (z) n = z-s;
+	return n;
+}

src/string/wcstok.c

+#include <wchar.h>
+
+wchar_t *wcstok(wchar_t *s, const wchar_t *sep, wchar_t **p)
+{
+	if (!s && !(s = *p)) return NULL;
+	s += wcsspn(s, sep);
+	if (!*s) return *p = 0;
+	*p = s + wcscspn(s, sep);
+	if (**p) *(*p)++ = 0;
+	else *p = 0;
+	return s;
+}