[Bug tree-optimization/126026] phiprop should handle `a = PHI<&l0, &l1, &l2>; `bb:`goto *a;`

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126026

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
This looks more like missed backward jump-threading, I wouldn't add this to
phiprop, duplicating control flow is ... ugly?