[Bug tree-optimization/78731] [5 Regression] Possible bug with switch when optimization is turned on.

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78731

--- Comment #6 from Jeffrey A. Law <law at redhat dot com> ---
The patch is fine -- it can't hurt correctness and it's less invasive than
pulling out all the backedge handling like we did for later releases.

My only worry is that it's really a bandaid for code that is fundamentally
broken.  So we could well end revisiting this stuff again in the old releases.