[llvm] Reland [CGData] llvm-cgdata #89884 (PR #101461)

[Kyungwoo Lee via llvm-commits]

kyulee-com wrote:

@aemerson Thank you for reviewing RFC and unblocking this PR!

> currently llvm/lib/CodeGenData/, which I feel a bit confusing when llvm/lib/CodeGenTypes/ is present

@MaskRay What about `CGData` or something else to avoid this confusion? This library name also seems more consistent to the tool name, `llvm-cgdata`.

https://github.com/llvm/llvm-project/pull/101461