[PATCH 1/5] libstdc++: Import the fast_float library

[Florian Weimer]

* Patrick Palka via Libstdc:

> This copies the fast_float library[1] into the compiled-in library
> sources.  We're going to use this library in our floating-point
> std::from_chars implementation for faster and more portable parsing of
> binary32/64 decimal strings.
>
> [1]: https://github.com/fastfloat/fast_float
>
> Series tested on x86_64, i686, ppc64, ppc64le and aarch64, does it
> look OK for trunk?

Missing Signed-off-by:?

> diff --git a/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE b/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE
> new file mode 100644
> index 00000000000..26f4398f249
> --- /dev/null
> +++ b/libstdc++-v3/src/c++17/fast_float/LICENSE-APACHE
> @@ -0,0 +1,190 @@
> +                                 Apache License
> +                           Version 2.0, January 2004
> +                        http://www.apache.org/licenses/

> diff --git a/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT b/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT
> new file mode 100644
> index 00000000000..2fb2a37ad7f
> --- /dev/null
> +++ b/libstdc++-v3/src/c++17/fast_float/LICENSE-MIT
> @@ -0,0 +1,27 @@
> +MIT License
> +
> +Copyright (c) 2021 The fast_float authors

You also need to include the README file, which makes it clear that
recipients can choose between Apache and MIT.  GCC needs to use the MIT
option, I think.

Thanks,
Florian