message: fix(runtime-core) Remove a warning for `unused_parens`.
  The behavior of `unused_parens` has changed since Rust 1.39. A warning
  is then raised. This patch fixes that.
diff: @@ -458,8 +458,8 @@ macro_rules! impl_traits {
  ( $( WasmExternType::from_native($x) ),* )
  }
  - fn into_c_struct(self) -> Self::CStruct {
  #[allow(unused_parens, non_snake_case)]
  + fn into_c_struct(self) -> Self::CStruct {
  let ( $( $x ),* ) = self;
  $struct_name ( $( WasmExternType::to_native($x) ),* )
  @@ -469,7 +469,7 @@ macro_rules! impl_traits {
  &[$( $x::Native::TYPE ),*]
  }
  - #[allow(non_snake_case)]
  + #[allow(unused_parens, non_snake_case)]
  unsafe fn call<Rets>(
  self,
  f: NonNull<vm::Func>,
  @@ -479,7 +479,6 @@ macro_rules! impl_traits {
  where
  Rets: WasmTypeList
  {
  - #[allow(unused_parens)]
  let ( $( $x ),* ) = self;
  let args = [ $( $x.to_native().to_binary()),* ];
  let mut rets = Rets::empty_ret_array();
  