[Bug rtl-optimization/85805] [7/8 Regression] Wrong code for 64 bit comparisons on avr-gcc

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85805

--- Comment #14 from Segher Boessenkool <segher at gcc dot gnu.org> ---
I backported it anyway.