[llvm] [ArrayRef] Add constructor from iterator_range<U*> (NFC). (PR #137796)

[Jakub Kuderski via llvm-commits]

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@@ -255,6 +255,26 @@ TEST(ArrayRefTest, ArrayRefFromStdArray) {
   }
 }
 
+TEST(ArrayRefTest, ArrayRefFromIteratorRange) {
+  std::array<int, 5> A1{{42, -5, 0, 1000000, -1000000}};
+  ArrayRef<int> A2 = make_range(A1.begin(), A1.end());
+
+  EXPECT_EQ(A1.size(), A2.size());
+  for (std::size_t i = 0; i < A1.size(); ++i) {
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kuhar wrote:

nit: You can use `EXPECT_THAT(A2, ElementsAreArray(A1))`

https://github.com/llvm/llvm-project/pull/137796