[Bug tree-optimization/126470] [15/16/17 Regression] Wrong operand check on a != 0 ? a / b : 0 -> a / b iff b is nonzero fold since r15-307

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126470

--- Comment #3 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 65171
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65171&action=edit
testing this patch