[clang] [Clang] [NFC] Tablegen component diags headers (PR #134777)

[via cfe-commits]

Sirraide wrote:

> ⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️
> 
> You can test this locally with the following command:
> View the diff from clang-format here.

clang-format seems to be having a stroke here. It’s suggesting indenting `namespace clang {` and everything in it even though it’s a top-level namespace defintion. I think this might be because the rest of the file is already quite weirdly formatted: the `namespace diag { ... }` block above the `#include` line is indented even though we don’t usually do that (anymore), which might be confusing it.

I think we should just ignore this because it’d probably take reformatting the entire file (or at least everything before the `#include` that this patch adds) to fix this.

https://github.com/llvm/llvm-project/pull/134777