Comment out @testable and @_spi

[davidungar]

For now, comment out testable and _spi, which makes it easier to try the driver out with various versions of the compiler.
Someday, we can either uncomment the @SPI's, or we can move components into sub-modules. What do you think?

[davidungar]

@swift-ci please test

[artemcm]

This is much less than I thought.
We should make sure we test this against ToT of swift following these steps:
https://github.com/artemcm/swift-driver/#testing-against-swift-compiler-trunk

[davidungar]

This is much less than I thought.
We should make sure we test this against ToT of swift following these steps:
https://github.com/artemcm/swift-driver/#testing-against-swift-compiler-trunk

Great thought! Trying this at swiftlang/swift#35000

[davidungar]

@swift-ci please test

[davidungar]

@artemcm Looks like swiftlang/swift#35000 passed. Does this PR merit approval?

[davidungar]

@swift-ci please test

[owenv]

In hindsight, I probably shouldn't have started introducing @_spi into the codebase so early. This LGTM, and it should be easy to improve on once the feature is more stable

[owenv]

nit: We can probably drop the @testable comments, I think we're better off never bringing them back assuming we can eventually start using @_spi again.

[davidungar]

Thanks, @owenv !

[davidungar]

@swift-ci please test