[Bug bootstrap/66448] [6 Regression] Bootstrap fails on darwin after r224161

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66448

--- Comment #9 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> Created attachment 35718
>   --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35718&action=edit
> Tentative patch for issue #3

The patch does not fix the

../../work/gcc/ipa-pure-const.c:1636:1: error:
'{anonymous}::pass_ipa_pure_const::pass_ipa_pure_const(gcc::context*)' defined
but not used [-Werror=unused-function]

issue.