Change to search_n

[Paolo Carlini]

Hi everyone,

> Generally it looks good to me, I don't really have much else to say :) 
> My only very slight worry is that as these algorithms are fiddled with 
> they get ever larger :)

therefore, I would lean toward adding this change to mainline, after 
benchmarking on a few targets, of course. Chris, do you have ready any 
check-performance numbers??? (what we have search_n.cc for, otherwise?!? ;)

Still, sorry, I don't believe this change qualifies as "minor" and only 
Chris can appear in the ChangeLog, given the FSF rules.

Paolo.