[clang] [analyzer] Handle [[assume(cond)]] as __builtin_assume(cond) (PR #116462)

[Balazs Benics via cfe-commits]

steakhal wrote:

This looks really good. I'll come back and push some changes to your branch to make it more similar with our coding style.
And maybe adding a few more tests. I'll expect you to then have a look at the commits I push and report back if you agree with those.
Once that is done, we can probably merge this PR.

Thank you for the PR.

https://github.com/llvm/llvm-project/pull/116462