The merge probably got wrong as there are some problems probably due to the
experiment begining with CR deferred evaluation. With nbench/ppc, performance
improvement was around 2x. With nbench on x86, performance improvement was
around 4x on average.
Incompatible change: instr_info_t has a new field in the middle. But since
insertion of PPC_I(XXX) identifiers is auto-generated, there is no problem.