[Bug target/123544] [16 Regression] AArch64: Wrong code at -O1

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123544

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note removing the uninitialized variable, still causes a failure.
That is fixing backsmith_pure_0 to be:

int8_t backsmith_pure_0() {return 0;}