anchor.diff:              currentOrder = order;
               if (optional("var", token)) {
                 reportRecoverableErrorCodeWithToken(
  -                  token, codeExtraneousModifier);
  +                  token, fasta.codeExtraneousModifier);
               } else if (optional("const", token)) {
                 if (getOrSet != null) {
                   reportRecoverableErrorCodeWithToken(
  -                    token, codeExtraneousModifier);
  +                    token, fasta.codeExtraneousModifier);
                   continue;
                 }
               } else if (optional("external", token)) {
  
positive.code:     } else {
        if (varFinalOrConst != null) {
          if (optional("const", varFinalOrConst)) {
            reportRecoverableErrorCode(name, codeConstFieldWithoutInitializer);
          } else if (isTopLevel && optional("final", varFinalOrConst)) {
            reportRecoverableErrorCode(name, codeFinalFieldWithoutInitializer);
          }
        }
        listener.handleNoFieldInitializer(token);
  
negative.code:           return parseYieldStatement(token);
  
          case AsyncModifier.Async:
            reportRecoverableErrorCode(token, fasta.codeYieldNotGenerator);
            return parseYieldStatement(token);
        }
        throw "Internal error: Unknown asyncState: '$asyncState'.";
  