Fix some warnings on nightly (#1409)

Author: alexcrichton

crates/wasm-mutate/src/mutators/codemotion/ir.rs

@@ -185,22 +185,6 @@ pub trait AstWriter {
         Ok(())
     }
 
-    /// Default encoding for code node
-    ///
-    /// This function is called by the defaut implementation
-    /// of the `write_code` method
-    fn write_code_default<'a>(
-        &self,
-        ast: &Ast,
-        nodeidx: usize,
-        range: Range<usize>,
-        newfunc: &mut Function,
-        operators: &Vec<OperatorAndByteOffset>,
-        input_wasm: &'a [u8],
-    ) -> crate::Result<()> {
-        self.write_code(ast, nodeidx, range, newfunc, operators, input_wasm)
-    }
-
     /// Encoding discriminator for the Ast nodes
     ///
     /// It calls the corresponding methods depending on the node type

crates/wasm-mutate/src/mutators/peephole.rs

@@ -39,9 +39,7 @@ use crate::{
     Error, ErrorKind, ModuleInfo, Result, WasmMutate,
 };
 use egg::{Rewrite, Runner};
-use rand::{prelude::SmallRng, Rng};
-use std::ops::Range;
-use std::{borrow::Cow, fmt::Debug};
+use rand::Rng;
 use wasm_encoder::{CodeSection, ConstExpr, Function, GlobalSection, Module, ValType};
 use wasmparser::{CodeSectionReader, FunctionBody, GlobalSectionReader, LocalsReader};
 
@@ -447,38 +445,6 @@ impl Mutator for PeepholeMutator {
     }
 }
 
-impl Debug for Box<dyn CodeMutator> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_tuple("Code mutator").finish()
-    }
-}
-
-pub(crate) trait CodeMutator {
-    fn mutate(
-        &self,
-        config: &WasmMutate,
-        rnd: &mut SmallRng,
-        operator_index: usize,
-        operators: Vec<OperatorAndByteOffset>,
-        funcreader: FunctionBody,
-        body_range: Range<usize>,
-        function_data: &[u8],
-    ) -> Result<Function>;
-
-    /// Returns if this mutator can be applied to the opcode at index i
-    fn can_mutate<'a>(
-        &self,
-        config: &'a WasmMutate,
-        operators: &[OperatorAndByteOffset<'a>],
-        at: usize,
-    ) -> Result<bool>;
-
-    /// Provides the name of the mutator, mostly used for debugging purposes
-    fn name(&self) -> Cow<'static, str> {
-        std::any::type_name::<Self>().into()
-    }
-}
-
 // This macro is meant to be used for testing deep mutators
 // It receives the original wat text variable, the expression returning the mutated function and the expected wat
 // For an example, look at SwapCommutativeOperator