[clang-tools-extra] [clang-tidy] Enable `modernize-return-braced-init-list`'s tests in C++11 (PR #158196)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> Maybe then we could fail test if `std` flag isn't passed to `check_clang_tidy.py`? This will encourage all new developers to set c++ standard explicitly all the time.

This could be a problem for downstream users, but not a very significant one. To preserve current behavior, we could make a flag `enable-default-standard` or something similar.



https://github.com/llvm/llvm-project/pull/158196