[committed] libstdc++: Add .editorconfig files

[François Dumont]

On 16/09/2024 11:23, Jonathan Wakely wrote:
> On Mon, 16 Sept 2024 at 10:19, Jonathan Wakely wrote:
>> As mentioned in the Q&A session in Prague, I've been using these files
>> for years in my local GCC tree to help with formatting libstdc++ files.
>> I'll come up with similar files for the top-level and elsewhere in the
>> GCC tree. As Jakub mentioned, we certainly don't want to trim trailing
>> whitespace from testsuite files, because some of those files are
>> specifically testing correct handling of whitespace.
>>
>> Editorconfig only handles the most basic settings (but those are things
>> we shouldn't be wasting our time doing by hand): trailing whitespace,
>> tabs vs spaces, number of columns to indent etc. For proper formatting
>> of code in libstdc++ I use https://github.com/mattkretz/vim-gnuindent
>> which does a great job (neither GNU indent nor clang-format can format
>> things the way we do it in libstdc++).
> Arsen mentioned that he has some similar emacs config for formatting
> libstdc++ code which should probably be added to the repo somewhere (I
> don't know enough about emacs to know where that should be, or how to
> make it only apply to the libstdc++ sub-directory).

Looks like there are emacs addins to consider .editorconfig files. Not 
good enough ?