The _Heap_Extend() has now the same signature as _Heap_Initialize().
The 4th parameter is ignored (page size in _Heap_Initialize()).
Add Heap_Area and Heap_Initialization_or_extend_handler.
Add and test _Heap_No_extend().
This helps to do a table based heap initialization and extension.
Create a table of Heap_Area elements and iterate through it. Set the
handler to _Heap_Initialize() in the first iteration and then to
_Heap_Extend().