[PATCH][_GLIBCXX_INLINE_VERSION] Fix <contracts>

[Jonathan Wakely]

On Wed, 20 Sept 2023 at 05:51, François Dumont via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
>
> libstdc++: Remove std::constract_violation from versioned namespace

Spelling mistake in contract_violation, and it's not
std::contract_violation, it's std::experimental::contract_violation

>
> GCC expects this type to be in std namespace directly.

Again, it's in std::experimental not in std directly.

Will this change cause problems when including another experimental
header, which does put experimental below std::__8?

I think std::__8::experimental and std::experimental will become ambiguous.

Maybe we do want to remove the inline __8 namespace from all
experimental headers. That needs a bit more thought though.

>
> libstdc++-v3/ChangeLog:
>
>      * include/experimental/contract:
>      Remove _GLIBCXX_BEGIN_NAMESPACE_VERSION/_GLIBCXX_END_NAMESPACE_VERSION.

This line is too long for the changelog.

>
> It does fix 29 g++.dg/contracts in gcc testsuite.
>
> Ok to commit ?
>
> François