message: Use vec.push instead of .insert for vmctx arg
diff: @@ -459,8 +459,8 @@ impl<'env, 'module, 'isa> FuncEnvironment for FuncEnv<'env, 'module, 'isa> {
  // Build a value list for the indirect call instruction containing the call_args
  // and the vmctx parameter.
  let mut args = Vec::with_capacity(call_args.len() + 1);
  + args.push(vmctx_ptr);
  args.extend(call_args.iter().cloned());
  - args.insert(0, vmctx_ptr);
  Ok(pos.ins().call_indirect(sig_ref, func_ptr, &args))
  }
  @@ -485,8 +485,8 @@ impl<'env, 'module, 'isa> FuncEnvironment for FuncEnv<'env, 'module, 'isa> {
  .expect("missing vmctx parameter");
  let mut args = Vec::with_capacity(call_args.len() + 1);
  + args.push(vmctx);
  args.extend(call_args.iter().cloned());
  - args.insert(0, vmctx);
  Ok(pos.ins().call(callee, &args))
  }
  @@ -532,8 +532,8 @@ impl<'env, 'module, 'isa> FuncEnvironment for FuncEnv<'env, 'module, 'isa> {
  let sig_ref = pos.func.dfg.ext_funcs[callee].signature;
  let mut args = Vec::with_capacity(call_args.len() + 1);
  + args.push(imported_vmctx_addr);
  args.extend(call_args.iter().cloned());
  - args.insert(0, imported_vmctx_addr);
  Ok(pos
  .ins()
  