Cover your kid's remaining eye and lock up the pets for the great old ones

Cover your kid's remaining eye and lock up the pets for the great old ones
have been disturbed: rework the linker script and then enable RELRO support
on all but mips64 (something something padding) and m88k (untested).
This extends the RO coverage from just .got and .cdtors to also include
.openbsd.randomdata, .jcr, .dynamic, and .data.rel.ro., and moves more
segments from the text section to the rodata section.  Depends on the
previous csu and ld.so work; reinstall those *before* rebuilding ld, or
just get a snapshot.

clues from kettenis
assistance testing and ok deraadt@