fixed a bug in a class field lookup function in the parser

This bug was originally reported by Juan. The following code
would not parse:

class B;
class C; 

class B{
  struct D{};  

  int * i;
  void foo(int * );

void B::foo(int * u){


The error message was:
rainier_24:pc++ -unparse l.c
Error on line 10 of l.c:  Undefined symbol 'i'

I have patched up the parser so now it seems to be able to handle  
cases like the example above. As always, if you notice any unusual
behavior, let me know.  --Beata