[Bug rtl-optimization/90706] [10/11/12/13 Regression] Useless code generated for stack / register operations on AVR

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90706

--- Comment #17 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
I've reverted my patch as it resulted in two new PRs.  I'll do more work on
this PR and I'll start this job in Jan.