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

[Stephen Tozer via llvm-commits]

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@@ -1869,6 +1870,7 @@ DIExpression *DIExpression::append(const DIExpression *Expr,
 
   // Copy Expr's current op list.
   SmallVector<uint64_t, 16> NewOps;
+  uint64_t OpCount = 0;
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SLTozer wrote:

Unused variable?

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