We have to be sure that the bugs fixed in the previous patches also apply to
nvim_win_call.
Checking v8.1.2124 and v8.2.4026 is especially important as these patches were
only applied to win_execute, but nvim_win_call is also affected by the same
bugs. A lot of win_execute's logic can be shared with nvim_win_call, so factor
it out into a common macro to reduce the possibility of this happening again.