Worth noting that this changes behaviour somewhat: now if the receiver is of non-interface type but the callee is promoted from an embedded interface, we'll call this a non-interface call and propagate the receiver into it. Contrast the old PR which I think looked at getACalleeSource instead of getTarget, and would have maintained the same behaviour regarding that scenario.

@smowton Yes, good point about the difference. I've put up a new approach now, which uses getACalleeSource() to try to get the function being called when it's through a variable. This is all in the pursuit of re-merging #13767, but I am beginning to think it's pretty pointless. It seems that function variables are pretty much only used when passing functions around, so attempting to find the function being called using local flow almost never works. I tried on a bunch of real world databases I had loaded up already and only found one case where the old and new definitions differ, this variable being called here. So maybe I should just accept that my tests which were failing don't reflect real world usage of Go.

Sounds sensible. Happy to either merge or not; your choice.