Update to Rust 2018 edition (#632)

* initial cargo fix run

* Upgrade cranelift-entity crate

* Upgrade bforest crate

* Upgrade the codegen crate

* Upgrade the faerie crate

* Upgrade the filetests crate

* Upgrade the codegen-meta crate

* Upgrade the frontend crate

* Upgrade the cranelift-module crate

* Upgrade the cranelift-native crate

* Upgrade the cranelift-preopt crate

* Upgrade the cranelift-reader crate

* Upgrade the cranelift-serde crate

* Upgrade the cranelift-simplejit crate

* Upgrade the cranelift or cranelift-umbrella crate

* Upgrade the cranelift-wasm crate

* Upgrade cranelift-tools crate

* Use new import style on remaining files

* run format-all.sh

* run test-all.sh, update Readme and travis ci configuration
fixed an AssertionError also

* Remove deprecated functions

lib/serde/Cargo.toml

@@ -8,6 +8,7 @@ license = "Apache-2.0 WITH LLVM-exception"
 categories = ["no-std"]
 readme = "README.md"
 keywords = ["webassembly", "serde"]
+edition = "2018"
 
 [[bin]]
 name = "clif-json"

lib/serde/src/clif-json.rs

@@ -25,13 +25,6 @@
     )
 )]
 
-extern crate clap;
-extern crate cranelift_reader;
-extern crate serde_json;
-#[macro_use]
-extern crate serde_derive;
-extern crate cranelift_codegen;
-
 use clap::{App, Arg, SubCommand};
 use cranelift_reader::parse_functions;
 use std::fs::File;

lib/serde/src/serde_clif_json.rs

@@ -1,4 +1,5 @@
 use cranelift_codegen::ir::{Ebb, Function, Inst, InstructionData, Signature};
+use serde_derive::{Deserialize, Serialize};
 
 /// Serializable version of the original Cranelift IR
 #[derive(Clone, Debug, Hash, PartialEq, Eq, Serialize, Deserialize)]