[Bug tree-optimization/93321] Unlimited recursion in prepare_block_for_update

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93321

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 47679
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47679&action=edit
fully untested patch

This patch improves prepare_block_for_update but there might be others.