message: Have bril2json use full path for source position
diff: @@ -87,8 +87,11 @@ pub fn parse_abstract_program_from_read<R: std::io::Read>(
  let mut buffer = String::new();
  input.read_to_string(&mut buffer).unwrap();
  let parser = bril_grammar::AbstractProgramParser::new();
  +
  + let src_name = file_name.map(|f| std::fs::canonicalize(f).unwrap().display().to_string());
  +
  parser
  - .parse(&Lines::new(&buffer, use_pos, file_name), &buffer)
  + .parse(&Lines::new(&buffer, use_pos, src_name), &buffer)
  .unwrap()
  }
  