headers: Declare missing creat64() function

Signed-off-by: Martin Storsjö <martin@martin.st>
diff --git a/mingw-w64-headers/crt/io.h b/mingw-w64-headers/crt/io.h
index ac049e7..f396b6d 100644
--- a/mingw-w64-headers/crt/io.h
+++ b/mingw-w64-headers/crt/io.h
@@ -344,6 +344,7 @@
   int __cdecl chsize(int _FileHandle,long _Size) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
   int __cdecl close(int _FileHandle) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
   int __cdecl creat(const char *_Filename,int _PermissionMode) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
+  int __cdecl creat64(const char *_Filename,int _PermissionMode);
   int __cdecl dup(int _FileHandle) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
   int __cdecl dup2(int _FileHandleSrc,int _FileHandleDst) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
   int __cdecl eof(int _FileHandle) __MINGW_ATTRIB_DEPRECATED_MSVC2005;