[llvm] Introduce DIExpression::foldConstantMath() (PR #71718)

[Shubham Sandeep Rastogi via llvm-commits]

rastogishubham wrote:

@jmorse @adrian-prantl @pogo59 @felipepiovezan I think I have addressed most of the feedback that was given on this patch. Please have a look

https://github.com/llvm/llvm-project/pull/71718