swift

b626f46d - [Build] Determine the early SwiftSyntax build directory in build-script-impl

[Build] Determine the early SwiftSyntax build directory in build-script-impl Cross-compilation of the host depends on iteration over all of the host architectures within build-script-impl itself, so the computation of the build directory must occur in build-script-impl. Sink it down there to fix builds for multiple host architectures.