This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
put_fs_word() to fuword() and suword(). Linux words are 16 bits
but BSD words are 32-bits, at least on vax's. Writing a too-large
word trashed the neighbouring short word.
Bruce
