[llvm] Use DIExpression::foldConstantMath at the result of a Salvaged expression (PR #71721)

[Stephen Tozer via llvm-commits]

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@@ -2285,6 +2287,7 @@ void llvm::salvageDebugInfoForDbgValues(
           DIExpression::appendOpsToArg(SalvagedExpr, Ops, LocNo, StackValue);
       LocItr = std::find(++LocItr, DIILocation.end(), &I);
     }
+    SalvagedExpr = SalvagedExpr->foldConstantMath();
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SLTozer wrote:

This could be moved after the `break` immediately below, since SalvagedExpr is unused if we hit the break.

https://github.com/llvm/llvm-project/pull/71721