swift

1ce8b027 - build-script: Copy libclang_rt.a from the host toolchain for visionOS.

build-script: Copy libclang_rt.a from the host toolchain for visionOS. During the toolchain build, when building the Swift standard library for platforms other than macOS the `libclang_rt.a` needs to be copied out of the host SDK. That wasn't happening for visionOS. Resolves rdar://135023111.