non-algorithmic maintainers

[Paolo Bonzini]

We currently have 3 non-algorithmic maintainers:

loop optimizer          Zdenek Dvorak           ook@ucw.cz
loop optimizer          Daniel Berlin           dberlin@dberlin.org
libcpp                  Tom Tromey              tromey@redhat.com

Especially for the loop optimizer, the situation is a bit strange. 
There are no other maintainers for this specific area (only 
middle-end/GIMPLE/RTL maintainers); Daniel has never really been active 
in this area (except for the old lambda code and scev which has separate 
maintainers); Zdenek, while not very active lately, has basically 
written the loop optimizer and has always been helpful with reviews.

I don't think there is a particular reason to keep this category, whose 
boundaries have actually never been very clear.

Paolo