This is a cool feature.
'avx2' needs to be added to intel64-haswell CPU_FLAGS_X86. http://en.wikipedia.org/wiki/Haswell_%28microarchitecture%29
And I see that with your last update, the core-avx-i and intel64-ivybridge profiles are now the same--as they should be--but it may be a point of confusion. Indeed, it took some scrutiny for me to figure out which of the two to use.