rather than inlines. These are compiled with -fomit-frame-pointer and
work out pretty close to the original routines, but it might be a fraction
slower. The reason for doing this is to prevent the SWI_* and HWI_* values
from being compiled into drivers and lkms etc which is one of the things
that prevents the same lkm from being used on both SMP and UP kernels.
This gives us a lot more scope for experimenting with the splxxx
implementaton for SMP parallelism etc.
Reviewed by: bde
