Fix octal escape sequence reporting format (#626)

Author: frodi-karlsson

internal/scanner/scanner.go

@@ -1512,7 +1512,7 @@ func (s *Scanner) scanEscapeSequence(flags EscapeSequenceScanningFlags) string {
 			if flags&EscapeSequenceScanningFlagsRegularExpression != 0 && flags&EscapeSequenceScanningFlagsAtomEscape == 0 && ch != '0' {
 				s.errorAt(diagnostics.Octal_escape_sequences_and_backreferences_are_not_allowed_in_a_character_class_If_this_was_intended_as_an_escape_sequence_use_the_syntax_0_instead, start, s.pos-start, fmt.Sprintf("%02x", code))
 			} else {
-				s.errorAt(diagnostics.Octal_escape_sequences_are_not_allowed_Use_the_syntax_0, start, s.pos-start, code)
+				s.errorAt(diagnostics.Octal_escape_sequences_are_not_allowed_Use_the_syntax_0, start, s.pos-start, "\\x"+fmt.Sprintf("%02x", code))
 			}
 			return string(rune(code))
 		}