[Bug c++/119405] C++ for non gnu mode should set -ffp-contract=off just like C non-gnu modes

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119405

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
IMO the different behavior between gnu and non-gnu is odd.