AV *mro_linear_c3; /* cached c3 @ISA linearization */
HV *mro_nextmethod; /* next::method caching */
U32 cache_gen; /* Bumping this invalidates our method cache */
+ U32 pkg_gen; /* Bumps when local methods/@ISA change */
mro_alg mro_which; /* which mro alg is in use? */
};