To reproduce:

1. Download attached project "ThreadStackSizeCrashTestBed.zip" and open in Unity
2. Open "start" scene
3. Set Scripting Runtime Version to .NET 4.x
4. Set Scripting Backend to IL2CPP
5. Build for iOS or Android
6. Deploy the built project to the device
7. Press "256k" or "128k" button

Expected behavior: Xcode prints these logs:

Creating Thread!
Starting Thread!
Printing from a thread!!!!!

Actual behavior: Program crashes

Notes:
- Could not check on Windows Standalone and macOS Standalone because Build fails
- This issue appears on iOS and Android (IL2CPP)
- Stack Trace is shared in Comments section§
- If you use .NET 3.5 or Mono everything works as expected

Tested with:
- iPhone 7 Plus, iOS: 12.0 - Reproduced
- iPhone X, iOS: 11.3.1 - Reproduced
- Samsung Galaxy S8 - Reproduced

Reproduced on Unity 2017.4.0f1, 2017.4.16f1, 2018.2.18f1, 2018.3.0b12 and 2019.1.0a11