Tests don't compile on Windows

[RReverser]

Trying to run tests on Windows fails with following compilation errors:

error[E0425]: cannot find value `MAP_ANONYMOUS` in module `libc`
   --> src\simd.rs:668:48
    |
668 |     const MAP_ANONYMOUS: libc::int32_t = libc::MAP_ANONYMOUS;
    |                                                ^^^^^^^^^^^^^ not found in `libc`
help: possible candidate is found in another module, you can import it into scope
    |
298 |     use simd::test::MAP_ANONYMOUS;
    |

error[E0425]: cannot find value `PROT_READ` in module `libc`
   --> src\simd.rs:684:30
    |
684 |             let prot = libc::PROT_READ | libc::PROT_WRITE;
    |                              ^^^^^^^^^ not found in `libc`

error[E0425]: cannot find value `PROT_WRITE` in module `libc`
   --> src\simd.rs:684:48
    |
684 |             let prot = libc::PROT_READ | libc::PROT_WRITE;
    |                                                ^^^^^^^^^^ not found in `libc`

error[E0425]: cannot find value `MAP_PRIVATE` in module `libc`
   --> src\simd.rs:685:31
    |
685 |             let flags = libc::MAP_PRIVATE | MAP_ANONYMOUS;
    |                               ^^^^^^^^^^^ not found in `libc`

error[E0425]: cannot find function `mmap` in module `libc`
   --> src\simd.rs:689:36
    |
689 |             let first_page = libc::mmap(addr, length, prot, flags, fd, offset);
    |                                    ^^^^ not found in `libc`

error[E0425]: cannot find value `PROT_NONE` in module `libc`
   --> src\simd.rs:699:34
    |
699 |                 let prot = libc::PROT_NONE;
    |                                  ^^^^^^^^^ not found in `libc`

error[E0425]: cannot find function `mprotect` in module `libc`
   --> src\simd.rs:701:45
    |
701 |                 let mprotect_retval = libc::mprotect(addr, length, prot);
    |                                             ^^^^^^^^ not found in `libc`

error: aborting due to 7 previous errors

For more information about this error, try `rustc --explain E0425`.
error: Could not compile `jetscii`.

To learn more, run the command again with --verbose.

It would be better to use platform-independent crate like https://crates.io/crates/region.