Update the Windows packaging script.
As discussed here:
https://discourse.llvm.org/t/build-llvm-release-bat-script-options/63146/6
https://reviews.llvm.org/D127938#inline-1234370
Latest 7-zip versions (21.x) require administrator permissions to create symbolic links.
These are the changes in this patch:
- Check if any of the following conditions is true: a) Version of 7-zip is 20.x or older b) Script is running with administrator permissions
This line is saying the same as line 26. If we move the 7zip version check down before :begin, there would be no need to repeat it, and I think it would make sense to do that anyway.