mem_calloc :: fn (num: usize, size: usize) *u8
Allocates count of bytes on heap using default allocator and
return pointer to begin of this allocated block. Resulting
block is set to 0 value.
mem_free to free allocated memory when it's no longer
numCount of items to be allocated.
sizeItem size in bytes.
Pointer to begin of the new allocated block of memory.