[Bug c++/127434] [14/15/16/17 regression] IPA-SRA introduces unconditional load from conditionally accessed indexing header at -O2

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127434

--- Comment #2 from Drea Pinski <pinskia at gcc dot gnu.org> ---
I am not 100% sure this is well defined code.

The reasoning is `butterfly->indexingHeader()` does not return a valid object
in the case of !hasHeader. So calling a method on that would be undefined.