Do not use parentheses around the declared symbol

GCC 8 doesn't like this.

src/pointer-analysis/value_set_fivrns.cpp

@@ -33,23 +33,23 @@ hash_numbering<irep_idt, irep_id_hash> value_set_fivrnst::function_numbering;
 static const char *alloc_adapter_prefix="alloc_adaptor::";
 
 #define forall_objects(it, map) \
-  for(object_map_dt::const_iterator (it) = (map).begin(); \
+  for(object_map_dt::const_iterator it = (map).begin(); \
   (it)!=(map).end(); \
   (it)++)
 
 #define forall_valid_objects(it, map) \
-  for(object_map_dt::const_iterator (it) = (map).begin(); \
+  for(object_map_dt::const_iterator it = (map).begin(); \
   (it)!=(map).end(); \
   (it)++) \
     if((map).is_valid_at((it)->first, from_function, from_target_index))
 
 #define Forall_objects(it, map) \
-  for(object_map_dt::iterator (it) = (map).begin(); \
+  for(object_map_dt::iterator it = (map).begin(); \
   (it)!=(map).end(); \
   (it)++)
 
 #define Forall_valid_objects(it, map) \
-  for(object_map_dt::iterator (it) = (map).begin(); \
+  for(object_map_dt::iterator it = (map).begin(); \
       (it)!=(map).end(); \
       (it)++) \
     if((map).is_valid_at((it)->first, from_function, from_target_index)) /* NOLINT(*) */