[Bug tree-optimization/128068] Gimple_walk_operand api should be modernized

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128068

--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Note when changing this update docs too
https://gcc.gnu.org/onlinedocs/gccint/Statement-and-operand-traversals.html