Moving Linux-specific stuff out of i386-tdep.c

[Andrew Cagney]

Mark Kettenis wrote:

> 1. Do we still care about the filename limits of older System V
>    systems?  i386-linux-nat.c is longer than 14 characters which is a
>    no-no according to the GNU conding standards.

Per other e-mail: no but (8.3 :-)

> 2. Should I postpone creating the new -tdep.c file until after the
>    release or not.  Andrew has been telling us to avoid gratuitous
>    changes to make it easier to apply outstanding patches.  But on the
>    other hand, after 5.0 is released, I hope to see a lot new patches
>    generated against 5.0.  So creating the new file before 5.0 would
>    make applying those new patches a lot easier.

I guess its the sigtramp stuff.

If the checkin was a straight cut/paste (without edits) I won't notice
:-)
Down the track, there will need to be ``i386-linux-tdep.h'' so that
i386-linux-nat.c can include it.  (Hmm, with i386-linux-tdep.c, no
wonder Eli raised a concern).

	Andrew