message: Add some missing spaces to the core pretty printer
diff: @@ -162,6 +162,7 @@ impl<'interner, 'arena> Context<'interner> {
  RcDoc::concat([
  RcDoc::concat([
  RcDoc::text("fun"),
  + RcDoc::space(),
  // TODO: Share with Term::Ann
  self.paren(
  prec > Prec::Top,
  @@ -193,6 +194,7 @@ impl<'interner, 'arena> Context<'interner> {
  RcDoc::concat([
  RcDoc::concat([
  RcDoc::text("fun"),
  + RcDoc::space(),
  if let Some(name) = param_name {
  self.string_id(*name)
  } else {
  