[Bug lto/66752] spec2000 255.vortex performance compiled with GCC is ~20% lower than with CLANG

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66752

--- Comment #15 from Jeffrey A. Law <law at redhat dot com> ---
Causes bootstrap failure on ppc64 that I haven't had time to dig into.