Nothing has changed - splitting effectively never kicked in without a
profile. Honza and I had discussed the idea that static profile
heuristics could eventually be used to distinguish hot vs cold bbs,
but that hasn't happened. What I didn't notice until recently was the
size increase in the .o files from varasm adding in unnecessary
sections and labels when this option was on. Unless and until static
heuristics are used to distinguish cold bbs in
probably_never_executed_bb_p, I don't think it makes sense to do
anything finer grained that just disabling the option.