rust-ptx-linker does not work on Windows

Unfortunately, due to LLVM dylib limitations, Windows targets are not supported. The issue can be worked around if the linker is built with a static LLVM, but this requires a tighter integration with the Rust build process. Currently, there is no work is done in this direction, but the situation might change. https://github.com/denzp/rust-ptx-linker#windows-users