[PATCH] Handle IA-64 signal handler frames, call dummy frames

[DJ Delorie]

> Wouldn't it make more sense to mangle the name of the xxx-nat.c file
> instead of the xxx-tdep.c file?

It's probably been discussed before, but what about using
subdirectories?

	 45	*-nat
	 40	*-tdep
	 27	remote-*
	  8	ser-*

	156	tm-*	(in config/*)
	 96	xm-*
	 77	nm-*

It seems like if we add native, target, and remote subdirs it would
clean things up a bit.

Also, why aren't the *-nat and *-tdep files in config/<platform>/ ?