It keeps bugging me that this keyword is recognized in IDEs, but not in N++. Here's a fix.
Revision 735 is quite old, you must have used the wrong repository URL. The current revision is 1103, you can find the repository here:
Obviously wchar_t was not the only missing keyword. I made a new patch to make the list complete based on this list for C++11.
Thank you for your patched.
It will be included in the next release.