[Bug tree-optimization/122493] is_eye in leela is not split because of empty basic block (merge_phi should be part of cfgcleanup instead of its own pass)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122493

--- Comment #2 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Yep, I think only reason to not do phi merging here would be if the analysis
validating the transformation or subsequent cleanup was expensive.  This is
easy enough, so removal of BBs probably will pay back.