[Bug other/90257] [9/10 Regression] 8% degradation on cpu2006 403.gcc starting with r270484

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90257

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 46253
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46253&action=edit
gcc9-pr90257.patch

Untested patch that fixes PR90178 even when the reversion of reversion of
reversion in lra-spills.c is reverted.

For the trunk, we could as well replace the lra-spills.c change with richi's
dce change or whatever else.  Just it seems to be wrong to rely on unoptimal IL
to perform proper optimizations.