[llvm] [DAGCombiner] Add combine for vector interleave of splats (PR #151110)

[Luke Lau via llvm-commits]

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@@ -145,4 +231,5 @@ declare <32 x i8> @llvm.vector.interleave2.v32i8(<16 x i8>, <16 x i8>)
 declare <16 x i16> @llvm.vector.interleave2.v16i16(<8 x i16>, <8 x i16>)
 declare <8 x i32> @llvm.vector.interleave2.v8i32(<4 x i32>, <4 x i32>)
 declare <4 x i64> @llvm.vector.interleave2.v4i64(<2 x i64>, <2 x i64>)
-
+declare <4 x i16> @llvm.vector.interleave2.v4i16(<2 x i16>, <2 x i16>)
+declare <8 x i16> @llvm.vector.interleave4.v8i16(<2 x i16>, <2 x i16>, <2 x i16>, <2 x i16>)
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lukel97 wrote:

Nit, I don't think we need to declare intrinsics anymore but happy to leave these here if just for consistency with the existing declarations

https://github.com/llvm/llvm-project/pull/151110