add explicit types for the visited flag and the exception regions

[r14296]

include/libfirm/firm_types.h

@@ -42,6 +42,9 @@ typedef unsigned long long ulong64;
 
 #endif /* _MSC_VER */
 
+typedef long          ir_visited_t;
+typedef unsigned long ir_exc_region_t;
+
 typedef struct dbg_info             dbg_info,            *dbg_info_ptr;
 typedef const struct _ident         ident,               *ir_ident_ptr;
 typedef struct ir_node              ir_node,             *ir_node_ptr;