Fix fuzz and wasi-c builds (#447)

* Fix the wasmtime-wasi-c crate build and upgrade it to Rust 2018.

* Fix the fuzz build.

wasmtime-wasi-c/Cargo.toml

@@ -7,6 +7,7 @@ categories = ["wasm"]
 repository = "https://github.com/CraneStation/wasmtime"
 license = "Apache-2.0 WITH LLVM-exception"
 readme = "README.md"
+edition = "2018"
 
 [dependencies]
 wasmtime-runtime = { path = "../wasmtime-runtime" }

wasmtime-wasi-c/src/instantiate.rs

@@ -2,6 +2,7 @@ use crate::host::{
     argv_environ_init, argv_environ_values, fd_prestats, fd_prestats_init, fd_prestats_insert,
     fd_table, fd_table_init, fd_table_insert_existing,
 };
+use crate::syscalls;
 use alloc::rc::Rc;
 use core::cell::RefCell;
 use cranelift_codegen::ir::types;
@@ -13,7 +14,6 @@ use std::ffi::CString;
 use std::fs::File;
 use std::mem;
 use std::os::unix::io::AsRawFd;
-use syscalls;
 use target_lexicon::HOST;
 use wasmtime_environ::{translate_signature, Export, Module};
 use wasmtime_runtime::{Imports, InstanceHandle, InstantiationError, VMFunctionBody};

wasmtime-wasi-c/src/lib.rs

@@ -1,12 +1,7 @@
-extern crate cranelift_codegen;
-extern crate cranelift_entity;
-extern crate cranelift_wasm;
-extern crate target_lexicon;
-extern crate wasmtime_environ;
-extern crate wasmtime_jit;
-extern crate wasmtime_runtime;
 #[macro_use]
 extern crate log;
+extern crate alloc;
+extern crate core;
 
 mod host;
 mod instantiate;

wasmtime-wasi-c/src/syscalls.rs

@@ -1,11 +1,11 @@
+use crate::host;
 use crate::host::{argv_environ_values, fd_prestats, fd_table};
 use crate::instantiate::WASIState;
+use crate::translate::*;
+use crate::wasm32;
 use core::convert::TryFrom;
 use cranelift_codegen::ir::types::{Type, I32, I64};
-use host;
 use std::{mem, ptr, slice, str};
-use translate::*;
-use wasm32;
 use wasmtime_runtime::VMContext;
 
 fn str_for_trace<'str>(ptr: *const i8, len: usize) -> Result<&'str str, str::Utf8Error> {

wasmtime-wasi-c/src/translate.rs

@@ -1,8 +1,8 @@
+use crate::host;
+use crate::wasm32;
 use core::convert::TryFrom;
-use host;
 use std::mem::{align_of, size_of, zeroed};
 use std::slice;
-use wasm32;
 use wasmtime_runtime::{Export, VMContext};
 
 /// Translate a wasm pointer into a native pointer.