Don't assume segments don't overlap
Don't assume segments don't overlap

I was cheating using lower_bound comparing with the last virtual address
here - the sort order is first address, so if there's a different object
in the middle of another, we fail. IT appears the aarch64 VDSO does
this.

peadar/pstack,peadar/pstack,peadar/pstack,peadar/pstack