[Bug tree-optimization/126139] phiopt does not if-convert half diamonds with multiple PHIs

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126139

--- Comment #5 from Drea Pinski <pinskia at gcc dot gnu.org> ---
I am going to fix PR 121029 which will allow this one to vectorize with SVE and
then come back to this one much later.