Fixes necessary for having no_std imports work with edition2018

src/stack_height/max_height.rs

@@ -1,4 +1,4 @@
-use std::vec::Vec;
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, BlockType, Type};
 use super::{resolve_func_type, Error};

src/stack_height/mod.rs

@@ -49,8 +49,8 @@
 //!   between the frames.
 //! - upon entry into the function entire stack frame is allocated.
 
-use std::string::String;
-use std::vec::Vec;
+use crate::std::string::String;
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, Type};
 use parity_wasm::builder;

src/stack_height/thunk.rs

@@ -1,8 +1,8 @@
 #[cfg(features = "std")]
-use std::collections::{HashMap as Map};
+use crate::std::collections::{HashMap as Map};
 #[cfg(not(features = "std"))]
-use std::collections::{BTreeMap as Map};
-use std::vec::Vec;
+use crate::std::collections::{BTreeMap as Map};
+use crate::std::vec::Vec;
 
 use parity_wasm::elements::{self, FunctionType, Internal};
 use parity_wasm::builder;