[llvm] [IR] Fix range-based for loop over MDOperands bug (PR #80737)

[Adrian Prantl via llvm-commits]

adrian-prantl wrote:

@kazutakahirata In hindsight your original patch would have benefitted from a pre-commit review.
@rastogishubham Since there's more than one problem with it, I think it's best if you just revert https://github.com/llvm/llvm-project/commit/e8512786fedbfa6ddba70ceddc29d7122173ba5e but still update and land your test since it showcases a code path that previously wasn't covered.

https://github.com/llvm/llvm-project/pull/80737