PR libstdc++/86272 Fix undefined __glibcxx_check_insert_range2

[Jonathan Wakely]

On 03/07/18 22:11 +0200, François Dumont wrote:
>Hi
>
>Â Â Â  I plan to commit attached patch to fix the __gnu_debug::string 
>undefined macro.
>
>Â Â Â  Is it ok the way I used some tests to now validate 
>__gnu_debug::string on check-debug ?

Yes, good idea. We don't want to do that for *every* basic_string
test, but doing it for a few of them means we cover the
__gnu_debug::string.

OK for trunk and the affected branches. Thanks.