[clang] [analyzer][NFC] Explain why operator new/delete should never be eval-called (PR #161370)

[Balázs Benics via cfe-commits]

balazs-benics-sonarsource wrote:

This relates to past patches like https://reviews.llvm.org/D41266 and https://reviews.llvm.org/D124845

https://github.com/llvm/llvm-project/pull/161370