Resurrect RTEMS_LINKER_SET_BEGIN() and RTEMS_LINKER_SET_END().
Add new macros RTEMS_LINKER_SET_ITEM_COUNT(),
RTEMS_LINKER_SET_IS_EMPTY(), and
RTEMS_LINKER_SET_FOREACH().
Remove confusing RTEMS_LINKER_SET_ASSIGN_BEGIN() and
RTEMS_LINKER_SET_ASSIGN_END().
Fix RTEMS_LINKER_SET_SIZE() to return the size in characters as
specified by the documentation.
Update #2408.
Update #2790.
4b579c5f51