[clang] [clang][CFG] Sequence RHS before LHS for overloaded assignment operators in CFG to match C++17 rules (PR #181113)

[Utkarsh Saxena via cfe-commits]

usx95 wrote:

### Merge activity

* **Feb 15, 1:53 PM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.com/github/pr/llvm/llvm-project/181113).


https://github.com/llvm/llvm-project/pull/181113