No other sub directory provides such a configuration option, so
drop it from the sim dir as well. This cleans up a good bit of
code in the process.
If people want to use custom flags for just the sim, they can
still run configure+make by hand in the sim subdir and use the
normal CFLAGS settings.
The common subdir sets up a cconfig.h file to hold checks for the common
code. In practice, most files still end up using config.h instead which
just leads to confusion.
Merge all the configure checks that went into cconfig.h into SIM_AC_COMMON
so we can drop the cconfig.h file altogether. Now there is only a single
config.h file like normal.
The compiler/C library should produce reasonable code for htonl/ntohl,
and at least glibc tries pretty hard to always produce good code for
them. This logic only had support for 32-bit x86 systems anymore, and
it's unlikely people were even opting into this, so drop it all.
The --enable-sim-hostendian flag was purely so people had an escape route
for when cross-compiling. This is because historically, AC_C_BIGENDIAN
did not work in those cases. That was fixed a while ago though, so we can
require that macro everywhere now and simplify a good bit of code.
Rather than re-invent endian defines, as well as maintain our own list
of OS & arch-specific includes, punt all that logic in favor of the bfd
ones already set up and maintained elsewhere. We already rely on the
bfd library, so leveraging the endian aspect should be fine.
No arch is using this anymore, and we want all new ports using the
hardware framework instead. Punt WITH_DEVICES and the two callbacks
device_io_{read,write}_buffer.
We can also punt the tconfig.h file as no port is using it anymore.
This fixes in-tree builds that get confused by picking up the wrong
one (common/ vs <port>/) caused by commit ae7d0cac8c.
Any port that needs to set up a global define can use their own
sim-main.h file that they must provide regardless.
