Fix unused use warnings.

lib/environ/src/lib.rs

@@ -39,9 +39,6 @@ use hashmap_core::HashMap;
 #[cfg(feature = "std")]
 use std::collections::HashMap;
 
-use cast;
-use cranelift_wasm;
-use failure;
 #[macro_use]
 extern crate failure_derive;
 

lib/jit/src/lib.rs

@@ -38,10 +38,6 @@ use std::collections::{hash_map, HashMap};
 
 #[macro_use]
 extern crate cranelift_entity;
-
-use failure;
-use region;
-
 #[macro_use]
 extern crate failure_derive;
 

lib/runtime/src/lib.rs

@@ -36,16 +36,10 @@ use hashmap_core::{map as hash_map, HashMap};
 #[cfg(feature = "std")]
 use std::collections::{hash_map, HashMap};
 
-use errno;
-use region;
-
 #[macro_use]
 extern crate lazy_static;
-use libc;
 #[macro_use]
 extern crate memoffset;
-use cast;
-use failure;
 #[macro_use]
 extern crate failure_derive;
 #[cfg(target_os = "windows")]

lib/wast/src/lib.rs

@@ -22,7 +22,6 @@
     )
 )]
 
-use failure;
 #[macro_use]
 extern crate failure_derive;