[Integrated Swift driver] Use the tools from SwiftPM's toolchain.
[Integrated Swift driver] Use the tools from SwiftPM's toolchain.

The Swift driver's toolchain and SwiftPM's toolchain might have slightly
different paths in them. For now, map to SwiftPM's toolchain. There
should be a more direct way to rectify these.

apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager