[clang] [clang] Add Bytes/Column types to TextDiagnostic (PR #165541)

[via cfe-commits]

https://github.com/Sirraide commented:

In my experience, it’s usually easier to abuse enums for this, i.e.
```c++
enum class Bytes : unsigned;
enum class Columns : unsigned;
```
and then define additional operators as needed.

https://github.com/llvm/llvm-project/pull/165541