[RFC 0/4] Fix recent sim/*/config.in fallout: frv, m32r, sh64, iq2000

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

Recently, a change requiring -ldl due to bfd plugin default changing
from off to on, spread throughout the generated configury files, for
simulators as well as gdb.  In that process, sim/*/config.in for the
sims below was regenerated for the first time since 2012.  This had
build-breaking fallouts for some simulator showing bloopers in changes
from around 2013-03-23, attempts enabling sim-hardware and
dv-sockser.o.  Here's my take on fixing that: let's return to the
state before those attempts.  This is a request-for-comments, I'll
commit this in a few days unless someone has a better idea, one that
lets these simulators build *without* --{enable,disable} options and
where committing this would still not be an incremental improvement.

All this seems to have started with building dv-sockser.o for *all*
targets and that failing for windows hosts.  I tried to find the
reason dv-sockser.o was enabled in the first place, but failed finding
anything earlier than the hint in
<http://sourceware.org/ml/gdb-patches/2013-03/msg00745.html>.  It
seems the introduction of (building) dv-sockser.o and enabling
sim-hardware for *all* sims from that time was just misguided.  After
these patches, all simulators now build, in particular those fixed
below without and with --enable-sim-hardware and
--disable-sim-hardware, but that's mainly because
SIM_AC_OPTION_HARDWARE has a bug; it forces the value of its first
parameter rather than making it the default for
--{enable,disable}-sim-hardware.  See sim/common/acinclude.m4 and the
generated configure files.

brgds, H-P