[clang] [analyzer] New optin.taint.TaintAlloc checker for catching unbounded memory allocation calls (PR #92420)

[Balazs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

I join Donát, and I agree that this looks good as it is.
I had a handful of final remarks but I have no strong opinion on any of the raised points.
Merge this, once you considered them and took action if you agreed.

https://github.com/llvm/llvm-project/pull/92420