No need, other people have already done the work: the paper 'Branch Prediction and the Performance of Interpreters' gave strong hints that Intel has been using ITTAGE at least since Haswell.

Edit: also, Intel branch predictors up to Core2 were well characterized and were not believed to be using NN.

[1] https://hal.inria.fr/hal-01100647/document ,discussed last year at HN.