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

[Shubham Sandeep Rastogi via llvm-commits]

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@@ -1998,6 +1997,286 @@ DIExpression::constantFold(const ConstantInt *CI) {
           ConstantInt::get(getContext(), NewInt)};
 }
 
+static bool isConstOperation(uint64_t Op) {
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rastogishubham wrote:

that is unfortunately taken by `DIExpression::isContant()` which doesn't do exactly the same thing, I have changed it to `isConstantVal`

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