The IL2CPP runtime does not properly fill the sockaddr_un structure that is passed to the bind() or connect() system calls when trying to bind or connect to a Unix-domain socket

To reproduce:

1. Download attached "UnixSocketFailRepro.zip" project and open in Unity
2. Enter to Play mode
3. Note that Console prints these messages:

"Socket path: /tmp/test.socket"
"Testing managed bind call."
"Testing data transfer (managed listen + managed connect)"
"Transferred managed: "MANAGED STRING (This means it works with Unity's implementation)""

4. Exit from Play mode
5. Build for Standalone (IL2CPP), iOS or Android (IL2CPP)
6. Deploy the Xcode project to the iOS device, run Standalone Build or deploy .apk on Android device

Expected Results: Logs shows the same messages as on Unity Editor Console
Actual Results: Observe that right after the log "Testing managed bind call" it prints:

"FAILED BIND with exception: System.Net.Sockets.SocketException: Access denied".

Notes:
- This issue appears on Standalone (IL2CPP), iOS and Android (IL2CPP)
- On Mono Scripting Backend everything seems to work as Expected

Tested with:
- iPhone XS, iOS: 12.0 - Reproduced
- iPhone 8 Plus, iOS: 12.0 - Reproduced
- iPhone 7 Plus, iOS: 12.0 - Reproduced
- Huawei P20 Pro (CLT-L29), Android 8.1.0, CPU: HiSilicon Kirin 970, GPU: Mali-G72 - Reproduced

Reproduced on Unity 2017.4.0f1, 2017.4.27f1, 2018.3.14f1, 2018.4.0f1, 2019.1.3f1, 2019.2.0b2 and 2019.3.0a3