[Bug libstdc++/119429] size_t __nargs = -1 in std::format

[desmond.rhodes at outlook dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119429

--- Comment #5 from Desmond Rhodes <desmond.rhodes at outlook dot com> ---
(In reply to Andrew Pinski from comment #1)
> Since this is well defined this is not a bug. The bug is clang allows
> reporting of this and saying it is undefined. Basically -fsanitize=integer
> is broken and should NOT be used with well defined code.

Hi, yes, it is well defined. However, it is non-sensical in most cases as I've
been bitten by this underflow bug often when writing for loop.