Switch to the OpenBSD implementations of the wide scanf functions.

This also gets us the C99 wcstoimax and wcstoumax, and a working fgetwc and
ungetwc, all of which are needed in the implementation.

This also brings several other files closer to upstream.

Change-Id: I23b025a8237a6dbb9aa50d2a96765ea729a85579
diff --git a/libc/include/wchar.h b/libc/include/wchar.h
index 12715c2..669ce8d 100644
--- a/libc/include/wchar.h
+++ b/libc/include/wchar.h
@@ -97,9 +97,12 @@
 extern wint_t            towlower(wint_t);
 extern wint_t            towupper(wint_t);
 extern wint_t            ungetwc(wint_t, FILE *);
-extern int               vfwprintf(FILE *, const wchar_t *, va_list);
-extern int               vwprintf(const wchar_t *, va_list);
-extern int               vswprintf(wchar_t *, size_t, const wchar_t *, va_list);
+extern int vfwprintf(FILE*, const wchar_t*, va_list);
+extern int vfwscanf(FILE*, const wchar_t*, va_list);
+extern int vswprintf(wchar_t*, size_t, const wchar_t*, va_list);
+extern int vswscanf(const wchar_t*, const wchar_t*, va_list);
+extern int vwprintf(const wchar_t*, va_list);
+extern int vwscanf(const wchar_t*, va_list);
 extern size_t            wcrtomb(char *, wchar_t, mbstate_t *);
 extern int               wcscasecmp(const wchar_t *, const wchar_t *);
 extern wchar_t          *wcscat(wchar_t *, const wchar_t *);