gdb macros fails

[leonp at plris.com (Leon Pollak)]

Hello, all.

I tried to use for the first time the gdb macros rtems_heap_walk and 
rtems_workspace_walk.
Both failed saying:
There is no member named front_flag.

I shall be very thankful for clarification where this flag may be (the macros 
file has the last change dated 7Aug2006, rtems is 4.7).

Many thanks ahead.
-- 
Leon