[Bug libstdc++/109921] c++17/floating_from_chars.cc: compile error: ‘from_chars_strtod’ was not declared in this scope

[br015 at umbiko dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109921

--- Comment #2 from Andreas Ziegler <br015 at umbiko dot net> ---
Apart from a small typo

-+  if (rec.ec == errc{})
++  if (res.ec == errc{})

this fixes the build error.