message: Use Box<[Type]>` inside of `FunctionType`
  This saves 16 bytes (on 64bit systems) on the stack for each `FunctionType` and
  additional space on the heap by not allowing resizing (like Vec does)
diff: @@ -229,9 +229,9 @@ impl ExternType {
  #[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
  pub struct FunctionType {
  /// The parameters of the function
  - params: Vec<Type>,
  + params: Box<[Type]>,
  /// The return values of the function
  - results: Vec<Type>,
  + results: Box<[Type]>,
  }
  impl FunctionType {
  @@ -242,8 +242,8 @@ impl FunctionType {
  Returns: Into<Vec<Type>>,
  {
  Self {
  - params: params.into(),
  - results: returns.into(),
  + params: params.into().into_boxed_slice(),
  + results: returns.into().into_boxed_slice(),
  }
  }
  