[Bug c++/81327] cast to void* does not suppress -Wclass-memaccess

[ville.voutilainen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81327

--- Comment #1 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Note that this currently blocks building Qt with gcc 8. We could work around it
by turning our void* casts to char* casts, but we have a preference for fixing
this problem in the compiler.