Slowness when right-clicking a function

I'm reporting it for 8 but this has actually been an issue for a fairly long time.

Sometimes (randomly) the right-click menu is extremely long to come up - takes a few seconds where the UI freezes.

Some seemingly simple refactoring actions also easily get stuck.

Here is a trace where the menu took 3/4 second to come up, followed by another 3/4 sec freeze when I hit the "Add method in CPP file" refactoring action. It seems that it also gets stuck in the classic C++ code model.

Note that here I really have simple code in the file I wanted to do this - there's maybe 1200 lines of my own code total, plus a few standard C++ headers and nothing else: I tried to generate the body for the "update()" method here: