ntdll: Add copies of two XDG env vars to the environment, and use those in winemenubuilder and shell32.
To solve https://bugs.winehq.org/show_bug.cgi?id=49987 and https://bugs.winehq.org/show_bug.cgi?id=58023 we have to remove these two XDG variables from the environment. This is a proposal that adds copies with a different name and after this they can be removed. If this is not the right way to go I guess I will hear something?