As part of getting ready for GCC 4, I've found that a number of arches 
don't build with gcc-3.4 when using gdb_mbuild.sh.  As an aid, and to 
stop me and presumably others from going round in circles, I've updated 
the MAINTAINERS file to both reflect current reality note the problem.

I look forward to seeing real fixes (which are hopefully both simple and 
obvious and can be committed as such).