[Bug rtl-optimization/63577] [4.9/5 Regression]: Huge compile time and memory usage with -O and not -fPIC

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63577

--- Comment #16 from Jeffrey A. Law <law at redhat dot com> ---
I'd agree it's too invasive to backport -- both changes are new optimizations
and there may well have been follow-up patches for both.  The potential for
destabilizing the release branches would seem to outweigh the benefits for
reducing the compile time on this code.