How to reproduce:
1. Open the attached 'TestProj2019.zip' project
2. Build for iOS
3. Open the Xcode project and deploy it to an iOS device

Expected result: Cube is present in the Scene
Actual result: Scene is empty and 'Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED' is thrown to the Xcode console

Reproducible with: 2018.4.29f1, 2019.4.15f1, 2020.1.14f1, 2020.2.0b9, 2021.1.0a6

Reproducible with:
iPad Air 2 (iOS 11.0.3)
iPad Air 2 (iOS 13.1.2)
iPhone 6 (customer's info)
iPhone 6s (iOS 14.1)
iPhone 7 (iOS 13.3)

Not reproducible with:
iPhone 8+ (iOS 12.0)
iPhone XR (iOS 13.4.1)
iPad 9.7’ 6th gen (iOS 14.2)

Notes:
- Reproducible on Metal; Not reproducible on Open GLES 3
- It can be made to compile while losing functionality by modifying DitherFade.cginc: Change line 58 from: float dither = _BayerMatrix[index]; to float dither = _BayerMatrix[0];
- Xcode output:
Compiled shader: Feral/Dither Opaque, pass: FORWARD, stage: vertex, keywords DIRECTIONAL LIGHTMAP_ON LIGHTMAP_SHADOW_MIXING SHADOWS_SHADOWMASK
Compiled shader: Feral/Dither Opaque, pass: FORWARD, stage: fragment, keywords DIRECTIONAL LIGHTMAP_ON LIGHTMAP_SHADOW_MIXING SHADOWS_SHADOWMASK
2020-10-22 11:24:56.848971-0600 Feral[357:154727] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
2020-10-22 11:24:56.849438-0600 Feral[357:154740] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
2020-10-22 11:25:07.005848-0600 Feral[357:154728] Compiler failed with XPC_ERROR_CONNECTION_INTERRUPTED
Metal: Error creating pipeline state (Feral/Dither Opaque): Compiler encountered an internal error
(null)