[clang] [clang-format]: Split alignment of declarations around assignment (PR #69340)

[Owen Pan via cfe-commits]

owenca wrote:

> @gedare can you fix the merge conflict on this one?

We don't want to merge this yet. See [here](https://github.com/llvm/llvm-project/issues/68079#issuecomment-1776826021).

https://github.com/llvm/llvm-project/pull/69340