message: fix(runtime-core) Remove warnings.
  Because we can use the `impl_traits!` macro with only one identifier,
  a warning is emitted saying the parenthesis are useless for this
  specific usecase. They are required for all the other usecases
  though. We can safely ignore this warning.
diff: @@ -310,6 +310,7 @@ macro_rules! impl_traits {
  where
  $( $x: WasmExternType ),*;
  + #[allow(unused_parens)]
  impl< $( $x ),* > WasmTypeList for ( $( $x ),* )
  where
  $( $x: WasmExternType ),*
  @@ -380,6 +381,7 @@ macro_rules! impl_traits {
  }
  }
  + #[allow(unused_parens)]
  impl< $( $x, )* Rets, Trap, FN > ExternalFunction<ExplicitVmCtx, ( $( $x ),* ), Rets> for FN
  where
  $( $x: WasmExternType, )*
  @@ -495,6 +497,7 @@ macro_rules! impl_traits {
  }
  }
  + #[allow(unused_parens)]
  impl< $( $x, )* Rets, Trap, FN > ExternalFunction<ImplicitVmCtx, ( $( $x ),* ), Rets> for FN
  where
  $( $x: WasmExternType, )*
  @@ -607,6 +610,7 @@ macro_rules! impl_traits {
  }
  }
  + #[allow(unused_parens)]
  impl<'a $( , $x )*, Rets> Func<'a, ( $( $x ),* ), Rets, Wasm>
  where
  $( $x: WasmExternType, )*
  