[clang] [llvm] [mlir] [InferAttrs] Mark errnomem-setting libcalls as such (PR #124742)

[Eli Friedman via llvm-commits]

https://github.com/efriedma-quic commented:

Please take a second look at your markings: in particular, syscalls with side-effects should be treated as modifying inaccessible memory.

https://github.com/llvm/llvm-project/pull/124742