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

[Donát Nagy via cfe-commits]

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

The change LGTM. I agree with @steakhal that `TaintedAlloc` would be a slightly better name, but the current one is also acceptable.

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