Building on unix fails when targeting windows

[Rjected]

When building a project cross-platform that depends on crunchy:

cargo build --target x86_64-pc-windows-gnu

This currently fails with an error like this:

error: couldn't read /home/runner/work/reth/reth/target/x86_64-pc-windows-gnu/debug/build/crunchy-f1c0e4cba7d0aa5b/out\lib.rs: No such file or directory (os error 2)
  --> /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/crunchy-0.2.3/src/lib.rs:37:1
   |
37 | include!(concat!(env!("OUT_DIR"), "\\lib.rs"));
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: this error originates in the macro `include` (in Nightly builds, run with -Z macro-backtrace for more info)

error: could not compile `crunchy` (lib) due to 1 previous error

I'm not sure why the lib.rs needs to be included like this, but now any project that uses crunchy requires that the host path separator is the same as the target path separator.

crunchy/src/lib.rs

Lines 36 to 40 in df1e539

	#[cfg(target_os = "windows")]
	include!(concat!(env!("OUT_DIR"), "\\lib.rs"));
	#[cfg(not(target_os = "windows"))]
	include!(concat!(env!("OUT_DIR"), "/lib.rs"));

[eira-fransham]

Closed by #17