[compiler-rt] [sanitizer_common] [Darwin] Replace pty with pipe on posix_spawn path for spawning symbolizer (PR #170809)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

https://github.com/llvm/llvm-project/pull/171560 to fix the usage of `stdin`/`stdout`

https://github.com/llvm/llvm-project/pull/170809