elf: stop assuming that PAGE_SIZE is 4KiB.
elf: stop assuming that PAGE_SIZE is 4KiB.

On some architectures, it's possible to make the kernel use 64KiB pages.
We've had some code in the elf section handling that aligned sections on
4KiB page boundaries regardless, instead of asking for the right page
size through sysconf(3).

Snaipe/Criterion,offa/Criterion,Snaipe/Criterion,offa/Criterion,Snaipe/Criterion,offa/Criterion,offa/Criterion,Snaipe/Criterion,offa/Criterion,Snaipe/Criterion