[clang] [clang-tools-extra] [Clang][Sema] Clarify structured binding diagnostic when initializer is missing (PR #181803)

[Giovanni B. via cfe-commits]

Z3rox-dev wrote:

> According to the content in [#181803 (comment)](https://github.com/llvm/llvm-project/pull/181803#discussion_r2816948888) , I think this PR uses AI to fix good first issue, which violates LLVM AI Policy. I will no longer review this PR.

The automatic Copilot review was an account setting I wasn’t aware of so I’ve disabled it. I did use AI tools to help navigate the codebase and accelerate the learning process, but I am fully aware of what I’m doing. The fix itself follows the approach suggested by AaronBallman in the abandoned PR #127924.

https://github.com/llvm/llvm-project/pull/181803