[llvm] [LLVM][ADT] Add `consume_front` member to ArrayRef (PR #146741)

[Jakub Kuderski via llvm-commits]

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@@ -104,6 +104,15 @@ TEST(ArrayRefTest, DropFront) {
   EXPECT_TRUE(AR1.drop_front(2).equals(AR2));
 }
 
+TEST(ArrayRefTest, ConsumeFront) {
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kuhar wrote:

We should also test `MutableArrayRef`

https://github.com/llvm/llvm-project/pull/146741