[Bug rtl-optimization/64164] [4.9/5 Regression] one more stack slot used due to one less inlining level

[patrick.marlier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64164

--- Comment #27 from Patrick Marlier <patrick.marlier at gmail dot com> ---
I confirm that the patch fixes the performance problem that I had. I guess the
patch is too complex to be backported.

Thanks a lot Alexandre for the patch and to all for the deep analysis!
(just waiting for review and commit :))