[Bug middle-end/94703] Small-sized memcpy leading to unnecessary register spillage unless done through a dummy union

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94703

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 48335
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48335&action=edit
untested patch

Patch, easier than expected.  Possibly needs some adjustment to the gimplifier,
we'll see.