1) Adds future RMI directories
2) Places intr_machdep.c in specfic files.arch pointing to the generic
intr_machdep.c. This allows us to have an architecture dependant intr_machdep.c
(which we will need for RMI) in the machine specific directory
3) removes intr_machdep.c from files.mips
4) Adds some TARGET_XLR_XLS ifdef's for the machine specific intra_machdep.h. We
may need to look at finding a better place to put this. But first I want to
get this thing compiling.
