[llvm-jitlink] Fix use of getaddrinfo(3) when connecting remote executor via TCP socket

Since llvm-jitlink moved from gethostbyname to getaddrinfo in D95477, it seems to no longer connect to llvm-jitlink-executor via TCP. I can reproduce this behavior on both, Debian 10 and macOS 10.15.7:

```
> llvm-jitlink-executor listen=localhost:10819
--
> llvm-jitlink --oop-executor-connect=localhost:10819 /path/to/obj.o
Failed to resolve localhost:10819
```

Reviewed By: rzurob

Differential Revision: https://reviews.llvm.org/D98579