Windows build broken

[Seeker14491]

The last commit broke the build on Windows:

error[E0308]: match arms have incompatible types                         ] 0/2: open
  --> src\lib.rs:68:13
   |
68 | /             match path_ref.to_str() {
69 | |                 Some(s) => s.replace("&", "^&"),
70 | |                 None => path_ref,
   | |                         -------- match arm with an incompatible type
71 | |             }
   | |_____________^ expected struct `std::string::String`, found reference
   |
   = note: expected type `std::string::String`
              found type `&std::ffi::OsStr`

I'm planning on sending a PR that replaces the Windows code with the approach rustup uses anyways, which will take care of this issue too.