[clang] [flang] [llvm] [mlir] [IR] Generalize !amdgpu.ignore.denormal.mode into !atomic.ignore.denormal.mode (PR #217585)

[Christian Sigg via llvm-commits]

chsigg wrote:

Thank you Nikita for the review and guidance.

- I removed the textual IR upgrade from LLParser.
- I moved the bitcode metadata upgrade into the existing instruction traversal loop.

https://github.com/llvm/llvm-project/pull/217585