[llvm] [mlir] [DebugInfo] Add symbolic branches to DIExpression (PR #210850)

[Felipe de Azevedo Piovezan via llvm-commits]

felipepiovezan wrote:

What is the problem this PR is trying to solve? This seems like a pretty big extension to the DIExpression language, and it's not clear what the motivation is.

https://github.com/llvm/llvm-project/pull/210850