[rfc/rft] Remove tm-alpha.h header file

[Mark Kettenis]

> Date: Fri, 5 Oct 2007 13:58:39 -0700
> From: Joel Brobecker <brobecker@adacore.com>
> 
> > Tested only to the extent to make sure everything still compiles;
> > if anyone with access to an Alpha machine could run a regression 
> > test, I'd appreciate it!  
> 
> We have some Tru64 machines available to us, but I haven't been able
> to run the testsuite on these machine for some time now :-(. I have
> looked at this patch, and it looks correct to me (FWIW).

I'll see if I can run the testsuite on OpenBSD/alpha this weekend.