[lldb] [llvm] [LLDB] Switch to using DIL as default implementation for 'frame var'. (PR #147887)

[Pavel Labath via llvm-commits]

labath wrote:

The process for that is [here](https://llvm.org/docs/GitHub.html#backporting-fixes-to-the-release-branches), though it's a bit unfortunate that a week has passed since then (I was OOO this week so I couldn't reply sooner). At this point, I'm no longer sure it makes sense to do that.

https://github.com/llvm/llvm-project/pull/147887