[lld] r249760 - [ELF2] Make the system page size a target-dependent property

[Rafael Espíndola via llvm-commits]

> Rounding up to a page here is one of the issues affecting LLD on
> FreeBSD that I posted about a couple of days ago (although it predates
> the change quoted above from r249760).  Rounding up puts the PT_INTERP
> and ELF ABI notes outside of the first page.
>
> As a local hack I changed it to round up to 512 to continue
> investigating other FreeBSD issues and that's sufficient for me to get
> further, but we need to be more clever than just reserving the first
> page for the PHDRs.

The real fix I think is to try to put more sections just after the
program headers and have a list of sections that must go there or we
error.

It is on my todo list, but comdats were first :-)

Cheers,
Rafael