[Bug preprocessor/58379] default mmap based implementation (mmap_gt_pch_get_address/mmap_gt_pch_use_address) is useless

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58379

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Well, it doesn't _rely_ on it - it basically makes systems where that is the
case work out of the box (every system pre address-space-randomization area).

If you have a system that randomizes then you have to re-define the hook.