[llvm] [ADT] Implement EnumeratedArray with std::array (NFC) (PR #158407)

[Jakub Kuderski via llvm-commits]

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@@ -38,11 +40,7 @@ class EnumeratedArray {
   using const_pointer = const ValueType *;
 
   EnumeratedArray() = default;
-  EnumeratedArray(ValueType V) {
-    for (IndexType IX = 0; IX < Size; ++IX) {
-      Underlying[IX] = V;
-    }
-  }
+  EnumeratedArray(ValueType V) { Underlying.fill(V); }
   EnumeratedArray(std::initializer_list<ValueType> Init) {
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kuhar wrote:

This could be a `llvm::copy`, no?

https://github.com/llvm/llvm-project/pull/158407