[Bug middle-end/66391] suboptimal code for assignment of SImode struct with bitfields

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66391

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So at -O2 we get decent code from GCC 9+ due to store merging which "undoes"
what SRA did.

But at -O3 the loop gets split into two.