XCode Version 11.5 Build Command Segmentation fault: 11 when a class fails to implement the correct protocol function signature

Originator:noel.weichbrodt
Number:rdar://FB7775274 Date Originated:6/24/2020
Status:Open Resolved:
Product:XCode Product Version:11.5
Classification:Swift Compiler Reproducible:Yes
 
Please describe the issue:
When running the Build command in XCode Version 11.5 (11E608c) on https://github.com/spokestack/spokestack-ios/commit/264963dafbe039fe65e2a033db1d60285f6fb2ea, a "Segmentation fault: 11" occurs.
Please list the steps you took to reproduce the issue:
When running the Build command in XCode on https://github.com/spokestack/spokestack-ios/commit/40f87f49076a0959c1f83d8a8054d5280a2a972a, the command completes successfully. 

The difference between the Build command causing a segfault and completing successfully is a single "throws" in a protocol function implementation. See https://github.com/spokestack/spokestack-ios/commit/264963dafbe039fe65e2a033db1d60285f6fb2ea for the diff.

I have attached the segfault stack dump and a zip of the project at https://github.com/spokestack/spokestack-ios/commit/264963dafbe039fe65e2a033db1d60285f6fb2ea that will segfault when the Build command is run.
What did you expect to happen?
When the Build command is run on the provided example project, I expected a "Type 'AppleSpeechRecognizer' does not conform to protocol 'SpeechProcessor'" error from the compiler.
What actually happened?
When the Build command is run on the provided example project, I receive a "Segmentation fault: 11" error from the compiler.

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