[clang] [llvm] [mlir] [IR][NFC] Rename insertDbgValueIntrinsic -> insertDbgValue (PR #212151)

[Orlando Cazalet-Hyams via cfe-commits]

https://github.com/OCHyams approved this pull request.

LGTM, thanks for tiding this up

As an aside, I think we could remove `DbgInstPtr` too at some point (not in this PR), as it's a union that was added to help the transitionary phase between intrinsics and records.

https://github.com/llvm/llvm-project/pull/212151