[clang] [analyzer] Adding taint analysis capability to unix.Malloc checker (PR #92420)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

> Have you considered applying the same heuristic to C++ array new allocations?

Actually, I'm almost certain that this patch already affects the C++ array new allocations, because `MallocMemAux` is called from the callback which handles the array new operator.

@dkrupp Please add a C++ test file with a few testcases which show the behavior of your commit when an unconstrained tainted size is passed to `operator new[]`.

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