[llvm-branch-commits] [clang] [clang][CIR] Merge the mlir::cir namespace into cir (PR #115386)

[Shoaib Meenai via llvm-branch-commits]

smeenai wrote:

The Windows CI error is an unrelated infra failure, but I don't know how to retry it.

https://github.com/llvm/llvm-project/pull/115386