Added some do_free_* functions and made them accept a zero argument. Rev: src/array.c:1.75 Rev: src/mapping.c:1.91 Rev: src/mapping.h:1.26 Rev: src/multiset.c:1.23 Rev: src/multiset.h:1.12 Rev: src/object.c:1.132 Rev: src/stralloc.c:1.84