[llvm] Support non-malloc functions in malloc+memset->calloc fold (PR #138299)

[Nikita Popov via llvm-commits]

nikic wrote:

As far as I know, Clang currently doesn't support declaring allocators in C using attributes (it only supports noalias via `__attribute__((malloc))`, but not alloc-family/allockind/allocptr/allocalign). So I'm not sure it makes sense to try to support something like xmalloc->xcalloc conversion on the LLVM side, when Clang doesn't even expose the basic functionality yet.

https://github.com/llvm/llvm-project/pull/138299