[clang] [CIR] Streamline creation of mlir::IntegerAttrs using mlir::Builder (PR #141830)

[Henrich Lauko via cfe-commits]

xlauko wrote:

### Merge activity

* **May 29, 10:36 AM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/141830).


https://github.com/llvm/llvm-project/pull/141830