[llvm] Add the 'initialized' attribute langref and support (PR #84803)

[Jan Voung via llvm-commits]

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@@ -362,6 +362,21 @@ class FoldingSetNodeID {
     }
   }
 
+  void AddRanges(const SmallVector<std::pair<int64_t, int64_t>, 16> &Ranges) {
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jvoung wrote:

Is it possible to use ArrayRef or something to not need specific SmallVector inline size of 16 here? "Prefer to use ArrayRef<T> or SmallVectorImpl<T> as a parameter type." under https://llvm.org/docs/ProgrammersManual.html#llvm-adt-smallvector-h

https://github.com/llvm/llvm-project/pull/84803