[llvm] [NFC] Move DIExpressionCursor to DebugInfoMetadata.h (PR #69768)

[Shubham Sandeep Rastogi via llvm-commits]

rastogishubham wrote:

@MaskRay I have subsequent patches that build on top of this change that I had to stop working on because of some other work so I didn't merge this patch as well, do you suggest I merge this patch or wait?

https://github.com/llvm/llvm-project/pull/69768