Support Swift 6/Xcode 16

[SimplyDanny]

14.x versions are no longer available on macOS 14 images as can be seen in a recent PR build.

Building successfully with Xcode 16 requires to update a few test dependencies. It especially seems to have issues parsing files with unknown dependencies now.

[SimplyDanny]

Hey @johnfairh! I'd appreciate your feedback on this PR and the other PRs building on top of it. 🙏

[johnfairh]

All the attribute / version / fixtures stuff looks good - the way I handled the WinSDK issue before is to shim them enough to make macOS SourceKit happy with the types. In hindsight I ought to have added a comment to the failing test as well...

I think this a bit more future-proof than rummaging through the json & keeping track of which / how many errors we expect - if the windows people do get interested in sourcekitten again then maybe they can centralise the shims or figure out a better approach. This at the top of WindowsError.swift means the testLibraryWrappersAreUpToDate() test runs unchanged:

#if !os(Windows)
// Shims for !windows SourceKit - see LibraryWrapperGeneratorTests.testLibraryWrappersAreUpToDate
private typealias WORD = UInt
private typealias DWORD = WORD
private typealias WCHAR = WORD
private let FORMAT_MESSAGE_ALLOCATE_BUFFER = 0
private let FORMAT_MESSAGE_FROM_SYSTEM = 0
private let FORMAT_MESSAGE_IGNORE_INSERTS = 0
private func FormatMessageW(_ a: DWORD, _ b: Int?, _ c: DWORD, _ d: DWORD, _ e: Any?, _ f: Int, _ g: Int?) -> DWORD { 0 }
#endif

[SimplyDanny]

All the attribute / version / fixtures stuff looks good - the way I handled the WinSDK issue before is to shim them enough to make macOS SourceKit happy with the types. In hindsight I ought to have added a comment to the failing test as well...

I think this a bit more future-proof than rummaging through the json & keeping track of which / how many errors we expect - if the windows people do get interested in sourcekitten again then maybe they can centralise the shims or figure out a better approach. This at the top of WindowsError.swift means the testLibraryWrappersAreUpToDate() test runs unchanged:

#if !os(Windows)
// Shims for !windows SourceKit - see LibraryWrapperGeneratorTests.testLibraryWrappersAreUpToDate
private typealias WORD = UInt
private typealias DWORD = WORD
private typealias WCHAR = WORD
private let FORMAT_MESSAGE_ALLOCATE_BUFFER = 0
private let FORMAT_MESSAGE_FROM_SYSTEM = 0
private let FORMAT_MESSAGE_IGNORE_INSERTS = 0
private func FormatMessageW(_ a: DWORD, _ b: Int?, _ c: DWORD, _ d: DWORD, _ e: Any?, _ f: Int, _ g: Int?) -> DWORD { 0 }
#endif

Thank you for the tip. That works without changes in the test.