Revert "Stubs for unsupported platforms"

Reverting, because this makes me uneasy in multiple ways. It seems to me
that not compiling on unsupported platforms is strictly superior than
failing at runtime. It should be up to the end users to make sure
that they do cfg-out libloading on platforms where libloading is not
supported.

src/lib.rs

@@ -46,58 +46,6 @@ use self::os::unix as imp;
 #[cfg(windows)]
 use self::os::windows as imp;
 
-// When running on an unsupported OS, libloading will compile but panic on any calls.
-#[cfg(not(any(unix, windows)))]
-mod imp {
-    use std::{fmt, marker};
-    use std::ffi::OsStr;
-
-    pub struct Library;
-
-    impl Library {
-        pub fn new<P: AsRef<OsStr>>(_filename: P) -> ::Result<Self> {
-            unimplemented!()
-        }
-
-        pub unsafe fn get<T>(&self, _symbol: &[u8]) -> ::Result<Symbol<T>> {
-            unimplemented!()
-        }
-    }
-
-    impl fmt::Debug for Library {
-        fn fmt(&self, _fmt: &mut fmt::Formatter) -> fmt::Result {
-            unimplemented!()
-        }
-    }
-
-    pub struct Symbol<T>(marker::PhantomData<T>);
-
-    impl<T> Symbol<Option<T>> {
-        pub fn lift_option(self) -> Option<Symbol<T>> {
-            unimplemented!()
-        }
-    }
-
-    impl<T> Clone for Symbol<T> {
-        fn clone(&self) -> Self {
-            unimplemented!()
-        }
-    }
-
-    impl<T> fmt::Debug for Symbol<T> {
-        fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
-            unimplemented!()
-        }
-    }
-
-    impl<T> ::std::ops::Deref for Symbol<T> {
-        type Target = T;
-        fn deref(&self) -> &T {
-            unimplemented!()
-        }
-    }
-}
-
 pub mod os;
 pub mod changelog;
 mod util;