[Bug rtl-optimization/92264] [10 Regression] Compile time hog in 521.wrf_r with -Ofast -march=znver2 -g since r276318

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92264

--- Comment #23 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #22)
> Created attachment 48063 [details]
> more localized caching
> 
> Like this.  Martin, can you also check the effect on this one?

We can actually simplify since we won't ever use non-NULL cached vals which
also means this patch is a no-op and should be worse than the existing
state :/