message: [language][move] Tweak some parser error message in response to review feedback
  Closes:
  Approved by: tzakian
diff: @@ -643,7 +643,7 @@ fn parse_pack_or_call<'input>(tokens: &mut Lexer<'input>) -> Result<Exp_, Error>
  }
  _ => {
  - let expected = "either a brace-enclosed pack expression or \
  + let expected = "either a brace-enclosed list of field expressions or \
  a parenthesized list of arguments for a function call";
  Err(unexpected_token_error(tokens, expected))
  }
  @@ -1314,7 +1314,7 @@ fn parse_file<'input>(tokens: &mut Lexer<'input>) -> Result<FileDefinition, Erro
  let loc = current_token_loc(tokens);
  return Err(vec![(
  loc,
  - "Unexpected text after end of main function".to_string(),
  + "Unexpected characters after end of main function".to_string(),
  )]);
  }
  FileDefinition::Main(Main { uses, function })
  