Changes: Fixes sysrq t to work under skas mode.  Adds macros to get 
register arguments from the jmp bufs in conjunction with a new 
function.  Changes the show_trace call to pass the correct task, not the 
current one.

Let me know what you want changed, jeff, i set vim to hardtabs, i hope 
the white space comes out okay, don't want to get you in trouble again.  
i ran this in both frame pointer and no frame pointer mode.
Allan