[clang] [compiler-rt] [Clang] Make `-Wreturn-type` default to an error in all language modes (PR #123470)

[via llvm-commits]

foxtran wrote:

I juts found this PR. Thank you, @Sirraide! I made a corresponding proposal for C language (C2y) to have a restriction at standard level rather than in compiler level: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3483.pdf
I think (and not only me) that the same proposal should be sent to C++ committee.


https://github.com/llvm/llvm-project/pull/123470