[Bug libstdc++/68276] ios_base::_M_grow_words should use new (std::nothrow)

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68276

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Oops, that was meant to be for Bug 68982