On 1.3F/i386 egcs-1.0.2 980315, source supped Sep 12 13:38 BST:

all ===> gnu/lib/libgcc
...
/usr/src/gnu/lib/libgcc/../../dist/gcc/libgcc2.c:
  In function `__throw':
    3736: warning: assignment makes pointer from integer without a cast


  /* Emit the stub to adjust sp and jump to the handler.  */
  if (new_exception_model)
    retaddr = __builtin_eh_stub ();
  else
    retaddr =  __builtin_eh_stub_old ();             <= 3736

retaddr: void *
__builtin_eh_stub_old(): 
  builtin_function ("__builtin_eh_stub_old", ptr_ftype_void,
                    BUILT_IN_EH_STUB_OLD, NULL_PTR);
  extern tree builtin_function
      PROTO((char *, tree, enum built_in_function function_, char *));
  ptr_ftype_void = build_function_type (ptr_type_node, endlink);
  ptr_type_node = build_pointer_type (void_type_node);
  void_type_node = make_node (VOID_TYPE);

So at a guess, ptr_ftype_void says that __builtin_eh_stub_old returns
a void *, yet from the compiler warning its an int that comes back?

Cheers,

Patrick