Fixed wrong type cast spotted by the intel compiler in our portale obstack.h.

[r28265]

include/libfirm/adt/obstack.h

@@ -495,7 +495,7 @@ __extension__								\
 ( (h)->temp.tempint = (char *) (obj) - (char *) (h)->chunk,		\
   ((((h)->temp.tempint > 0						\
     && (h)->temp.tempint < (h)->chunk_limit - (char *) (h)->chunk))	\
-   ? (int) ((h)->next_free = (h)->object_base				\
+   ? (PTR_INT_TYPE) ((h)->next_free = (h)->object_base				\
 	    = (h)->temp.tempint + (char *) (h)->chunk)			\
    : (((obstack_free) ((h), (h)->temp.tempint + (char *) (h)->chunk), 0), 0)))