We don't need to sort opcodes anymore, since we are using an O(1) hash
and not binary search. Instead, sort them in the order they first
appear in insns.dat; this lets us move all the pseudo-ops to a
contiguous range at the start of the file, for more efficient
handling.
Change the functions that process pseudo-ops accordingly.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>