[Bug target/127362] More masking cases that can be improved on RISC-V

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127362

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
I was thinking about forming andn during the last forwprop or during isel. See
pr115086 for a similar issue on aarch64 and where I had a stab at this before.