from  Benoît Perrot  <benoit@lrde.epita.fr>
        * src/common.hh,
        * src/mipsy.cc,
        * src/inst/exp.hh,
        * src/inst/register.hh,
        * src/vm/cpu.hh, src/vm/cpu.cc:
        Use STL type naming style on enumerations.