Incorrect handing of typedefs when testing

[yav]

Consider the following example, in a file called test.c:

typedef struct {                                                                 
  int x;                                                                            
} T;                                                                                
                                                                                 
void f(T *p) { p->x = 2; }       

The generated test-exec.c file contains an empty typedef declaration like this:

typedef T;

which defaults T to int and leads to great confusion.