anchor.diff:            nameContext = IdentifierContext.fieldInitializer;
             if (!token.isIdentifier) {
               // Recover from a missing identifier by inserting one.
  -            token = insertSyntheticIdentifier(beforeToken.next, nameContext);
  +            token = insertSyntheticIdentifier(beforeToken, nameContext);
               beforeToken = previousToken(periodAfterThis, token);
             }
             beforeNameToken = beforeToken;
  
positive.code:   }
  
    Token parseOperatorName(Token token) {
      // TODO(brianwilkerson) Accept the last consumed token.
      assert(optional('operator', token));
      Token next = token.next;
      if (next.isUserDefinableOperator) {
        listener.handleOperatorName(token, next);
        return next;
      } else if (optional('(', next)) {
        return ensureIdentifier(token, IdentifierContext.operatorName);
      } else {
        // Recovery
        // The user has specified an invalid operator name.
  
negative.code:     token = token.next;
      assert(optional('.', token));
      Token period = token;
      token = ensureIdentifier(token, context);
      listener.handleQualified(period);
      return token;
    }
  