We don't do anything useful with the data yet, but I'm gonna rewrite
the layout code to run off of the program header table instead.
This will allow us to map .text and .rodata sections in read-only memory.
The SpinLock was all backwards and didn't actually work. Fixing it exposed
how wrong most of the locking here is.
I need to come up with a better granularity here.
We load /_hello.o which just prints out a simple message.
It executes inside the kernel itself, so no fancy userspace process
or anything, but this is still so cool!
