[SLP][REVEC] Pre-commit test.

Author: HanKuanChen

llvm/test/Transforms/SLPVectorizer/revec-shufflevector.ll

@@ -105,3 +105,14 @@ entry:
   store <4 x i32> %2, ptr %6, align 4
   ret void
 }
+
+define void @test5(ptr %out) {
+entry:
+  %0 = shufflevector <8 x i32> zeroinitializer, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %1 = shufflevector <8 x i32> zeroinitializer, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  %2 = getelementptr inbounds i32, ptr %out, i64 0
+  %3 = getelementptr inbounds i32, ptr %out, i64 4
+  store <4 x i32> %0, ptr %2, align 4
+  store <4 x i32> %1, ptr %3, align 4
+  ret void
+}