[Bug c/67730] [5/6 Regression] No warning when returning NULL in void function

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67730

--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
Or perhaps we need to a new function (and a new entry in the guidelines) for
the case that we always want the expansion point.