For packet-scope allocation, there's no need to support realloc(), free()
cause memory will be garbage collected after packet dissection.
(and this allocator is much faster than full block allocator).
Change-Id: I73fdf708c3077f48f55bdcc71f4fa859e4ac2335
Reviewed-on: https://code.wireshark.org/review/1428
Reviewed-by: Anders Broman <a.broman58@gmail.com>
Jakub Zawadzki