[llvm-dev] Comments on GitHub commits?

[Stephan Bergmann via llvm-dev]

You can apparently leave comments on GitHub commits (instead of 
commenting at Phabricator, or directly sending a reply to the relevant 
commit mailing list and relevant CCs).  I once accidentally did that 
myself 
(<https://github.com/llvm/llvm-project/commit/4a6861a7e5b59be24a09b8b9782255d028e7aade#commitcomment-35540755>) 
and now (presumably because I'm member of some GitHub group) got mail 
about 
<https://github.com/llvm/llvm-project/commit/2724d9e12960cc1d93eeabbfc9aa1bffffa041cc#commitcomment-35724925>.

Do we want to allow such comments?

If we do, are intended recipients of such comments (esp. in a case like 
mine above, where there was no @... in the comment and I intended to 
reach at least the commit's author) reliably informed about them (i.e., 
is it guaranteed that they will receive a mail)?

If we don't, is there a way to block such comments on GitHub (and give a 
message about the preferred communication channels)?