Fix compile failure on iOS for Mac Catalyst support

[jakepetroules]

#356 fixed compile failure on iOS, which happens if you are adding CLI support for a Mac Catalyst app.

This patch also fixes the tests compilation.

Checklist

• I've added at least one test that validates that my change is working, if appropriate
• I've followed the code style of the rest of the project
• I've read the Contribution Guidelines
• I've updated the documentation if necessary

[jakepetroules]

@swift-ci please test

[natecook1000]

LGTM!