[compiler-rt] Link shared sanitizer runtime with libresolv for dn_expand (PR #116415)

[Aaron Puchert via llvm-commits]

aaronpuchert wrote:

> "blocking" in the case of rtsan means unsafe for real-time code (contains a syscall of any type). I would guess that any query to the DNS subsystem results in a system call.

My understanding is that they don't do any syscalls, they just "compress" or "expand" domain names for a DNS query or reply. Since they write into buffers allocated by the caller, I think they don't even do any allocations. But I didn't check this hypothesis.

https://github.com/llvm/llvm-project/pull/116415