[llvm] [llvm] Reduce memory footprint of Debug metadata nodes (PR #71227)

[Chih-Ping Chen via llvm-commits]

cchen15 wrote:

Please add @stevemerr and @bwyma from the DGI team as the reviewers.

Also, you may want to consider making this change in the upstream directly.

https://github.com/llvm/llvm-project/pull/71227