Adjust stack and memory break before initializing
Adjust stack and memory break before initializing

We have to make sure there is enough accessible memory for the stack, bss, got and
data sections before trying to initialize them. Right now we're getting
away with it only because the kernel is liberal in letting us use memory
we haven't yet asked for.

tock/libtock-c,tock/libtock-c,tock/libtock-c