GZSaveHnd
GZSaveHnd Get handle to data to not move during zone growth
#include <Memory.h> Memory Manager
returns Handle to data to avoid moving
When a custom zone-grow function is called, a data area call the "grow zone
root" should NOT be moved. GZSaveHnd returns a handle leading to that data.
Returns: a generic Handle; it leads to data that should not be moved, unlocked,
purged, etc.

Notes: GZSaveHnd should be used by applications that have a custom heap-zone
grow function (see SetGrowZone). That function should take care to avoid
moving, unlocking, or purging the data led to by the returned handle.
The global variable GZRootHnd (at 0x0328) contains this handle.