[llvm] Reapply "[MemProf] Streamline and avoid unnecessary context id duplication (#107918)" (PR #110036)

[Snehasish Kumar via llvm-commits]

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@@ -1379,7 +1379,15 @@ void CallsiteContextGraph<DerivedCCG, FuncTy, CallTy>::
   DenseSet<uint32_t> LastNodeContextIds = LastNode->getContextIds();
   assert(!LastNodeContextIds.empty());
 
+#ifndef NDEBUG
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snehasish wrote:

Here keeping `CreatedNode` and `PrevIterCreatedNode` around in the optimized build should have little impact. Can we  avoid the ifndef (and differing loop header) here and L1461-L1463?

https://github.com/llvm/llvm-project/pull/110036