Delete comment reference to non-existent method

  void setPredefines(const char *P) { Predefines = P; }

  void setPredefines(const std::string &P) { Predefines = P; }

  /// getIdentifierInfo - Return information about the specified preprocessor

  /// identifier token.  The version of this method that takes two character

  /// pointers is preferred unless the identifier is already available as a

  /// string (this avoids allocation and copying of memory to construct an

  /// std::string).

  /// Return information about the specified preprocessor

  /// identifier token.

  IdentifierInfo *getIdentifierInfo(StringRef Name) const {

    return &Identifiers.get(Name);

  }