Adopt a search path for bridgeable types in component modules (no longer just in Foundation)

[millenomi]

Required for the work in swiftlang/swift-corelibs-foundation#1799.

[jrose-apple]

Should we guard this under !canImport(Darwin), so it doesn't get used by accident on a system that doesn't have Swift Foundation?

[millenomi]

@jrose-apple All this code currently runs on all OSes, including where Swift Foundation is not available. As a reminder, Swift Foundation may be available and must be functional on Darwin as we target that platform for test purposes only (which is why all the search paths I introduce in this patch include the Swift-prefixed spelling of the Foundation modules to search in).

[millenomi]

cfr. swiftlang/swift-corelibs-foundation#1799

[millenomi]

@swift-ci please smoke test

[millenomi]

The Linux crash is expected without the SCF changes; the macOS pass was not. Trying to build a toolchain with this so that I can try building SCF on Darwin and reproduce the crash I'm seeing in swiftlang/swift-corelibs-foundation#1799

[millenomi]

Please test with the following:
apple/swift-clang#245
swiftlang/swift-package-manager#1914
swiftlang/swift-corelibs-foundation#1799

@swift-ci please test

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 6a39dc047993a6e61c12f8ee9cfb1b4b4a36a22a

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 6a39dc047993a6e61c12f8ee9cfb1b4b4a36a22a

[millenomi]

Please test with the following:
apple/swift-clang#245
swiftlang/swift-package-manager#1914
swiftlang/swift-corelibs-foundation#1799
apple/swift-lldb#1187

@swift-ci please test

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 3793e288ea748639328b42f29c22b377c5809d8d

[shahmishal]

Please update the base branch to main by Oct 5th otherwise the pull request will be closed automatically.

• How to change the base branch: (Link)
• More detail about the branch update: (Link)