[llvm] [VP] Refactor VectorBuilder to avoid layering violation. NFC (PR #99276)

[Fraser Cormack via llvm-commits]

================
@@ -100,11 +99,11 @@ class VectorBuilder {
                                  const Twine &Name = Twine());
 
   /// Emit a VP reduction intrinsic call for recurrence kind.
-  /// \param Kind        The kind of recurrence
+  /// \param RdxID       The intrinsic id of llvm.vector.reduce.*
----------------
frasercrmck wrote:

The majority of comments in `llvm/` use `intrinsic ID` as opposed to `intrinsic id`, so I think we should use that

https://github.com/llvm/llvm-project/pull/99276