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

[Daniel Krupp via cfe-commits]

dkrupp wrote:

- Handling of C++ operator new[] allocation was added to the checker with test cases
- The checker is renamed to optin.taint.TaintAlloc, as besides malloc it handles the c++ new array allocations too
- Test cases and documentation was updated

@NagyDonat , @steakhal  please check if any more update is needed. thanks.

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