[Bug tree-optimization/114403] [14 regression] LLVM miscompiled with -O3 -march=znver2 -fno-vect-cost-model since r14-6822-g01f4251b8775c8

[sjames at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114403

--- Comment #6 from Sam James <sjames at gcc dot gnu.org> ---
Modifying llvm/include/llvm/ADT/iterator.h like so helps (!):
```
#pragma GCC push_options
#pragma GCC optimize ("O0")
  friend bool operator==(const iterator_adaptor_base &LHS,
                         const iterator_adaptor_base &RHS) {
    return LHS.I == RHS.I;
  }
#pragma GCC pop_options
```