[Bug tree-optimization/120630] [16 regression] wrong code at -O{s,2,3} with "-fno-tree-loop-im -fno-tree-loop-optimize -fno-tree-ch" on x86_64-linux-gnu

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120630

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
This seems to pass with Jakub's fix for PR120629. Up to him if he wants a
non-PGO case or not. Given this involves disabling some passes too, not sure
it's strictly better as a testcase, but up to him.