[clang-tools-extra] Add new check: do not return 0; at the end of main() in C++ (PR #77586)

[Piotr Zegar via cfe-commits]

PiotrZSL wrote:

I'm closing this pull request, as both Carlos and Aaron already commented, closed also issue.
Please find some other issue to implement, if you got questions, you can always ask in issue, or on discord.
This check won't be merged, simply it's as Carols described "nano-optimization", specially that it will activate only on single function in entire project.

https://github.com/llvm/llvm-project/pull/77586