*** TEST MALLOC 04 ***
Initialize heap with some memory
sbrk(128)
sbrk(128)
sbrk(64)
Initialize heap with some memory - return address out of heap
sbrk(128)
sbrk(-128)
Initialize heap with some unaligned memory
sbrk(128)
sbrk(128)
sbrk(64)
*** END OF TEST MALLOC 04 ***