$NetBSD: patch-ob,v 1.1 2008/01/06 19:25:10 rillig Exp $

gcc4 complained:
gdbtypes.c:2961: error: invalid lvalue in increment

--- include/obstack.h.orig	2001-01-21 00:02:00.000000000 +0000
+++ include/obstack.h	2007-11-30 21:04:44.000000000 +0000
@@ -421,7 +421,7 @@ __extension__								\
 ({ struct obstack *__o = (OBSTACK);					\
    if (__o->next_free + sizeof (void *) > __o->chunk_limit)		\
      _obstack_newchunk (__o, sizeof (void *));				\
-   *((void **)__o->next_free)++ = ((void *)datum);			\
+   *((*(void ***)&(__o->next_free)))++ = ((void *)datum);		\
    (void) 0; })
 
 # define obstack_int_grow(OBSTACK,datum)				\
@@ -429,7 +429,7 @@ __extension__								\
 ({ struct obstack *__o = (OBSTACK);					\
    if (__o->next_free + sizeof (int) > __o->chunk_limit)		\
      _obstack_newchunk (__o, sizeof (int));				\
-   *((int *)__o->next_free)++ = ((int)datum);				\
+   *((*(int **)&(__o->next_free)))++ = ((int)datum);			\
    (void) 0; })
 
 # define obstack_ptr_grow_fast(h,aptr) (*((void **) (h)->next_free)++ = (void *)aptr)