[clang-tools-extra] [clang-tidy] Add new check bugprone-unintended-char-ostream-output (PR #127720)

[Oliver Stöneberg via cfe-commits]

firewave wrote:

> I am seeing this with an enum type which might be valid, working code but have not looked into it yet.

The warnings in question were correct. It exposed a behavior change introduced by fixing `performance-enum-size`.

https://github.com/llvm/llvm-project/pull/127720