[Bug tree-optimization/82224] Strict-aliasing not noticing valid aliasing of two unions with active members

[myriachan at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82224

--- Comment #5 from Melissa <myriachan at gmail dot com> ---
This originated from a Stack Overflow post "supercat" made (I'm the "Myria"
there).

https://stackoverflow.com/questions/46205744/is-this-use-of-unions-strictly-conforming/