*** HEAP WALK TEST ***
start with a system state != SYSTEM_STATE_UP
testing the _Heap_Walk_check_control() function
        test what happens if page size = 0
        set page size to a not CPU-aligned value
        set minimal block size to a not page aligned value
        set allocation area of the first block to be non page-aligned
        clear the previous used flag of the first block
        set the previous block size of the first block to an invalid value
        set invalid next block for last block
testing the _Heap_Walk_check_free_list() function
        no free blocks
        create a loop in the free list
        put a block outside the heap to the free list
        put a block on the free list, which is not page-aligned
        put a used block on the free list
Walk freshly initialized heap
Test the main loop
        set the blocksize so, that the next block is outside the heap
        walk a heap with blocks with different states of the previous-used flag
        create a block with a not page aligned size
        create a block with a size smaller than the min_block_size
        make a block with a size, so that the block reaches into the next block
        create a block with invalid successor
        make a block with a size, so that it includes the next block
test the _Heap_Walk_check_free_block() function
        set a previous size for the next block which is not equal to the size of the actual block
        clear the previous_used flag of the first free block after an used block
        take a free block out of the free list
test the output-function for the _Heap_Walk()
therefore use the (already tested) case with a page size of 0
PASS[0]: page size 0, min block size 16
	area begin 0x0202C4BC, area end 0x0202D4BC
	first block 0x0202C4C0, last block 0x0202D4B0
	first free 0x0202C4C0, last free 0x0202C4C0
FAIL[0]: page size is zero
*** END OF HEAP WALK TEST ***