[wasm] Implement 128-bit endian swap for simd type

src/compiler/simd-scalar-lowering.h

Index: src/compiler/simd-scalar-lowering.h
diff --git a/src/compiler/simd-scalar-lowering.h b/src/compiler/simd-scalar-lowering.h
index 3d5e3fc88135d2cd5f0ca0dc1831e9f699d01018..383b702f469a946eb2c3942eb64be42165cca11f 100644
--- a/src/compiler/simd-scalar-lowering.h
+++ b/src/compiler/simd-scalar-lowering.h
@@ -36,6 +36,13 @@ class SimdScalarLowering {
     kSimd1x8
   };
 
+#if defined(V8_TARGET_BIG_ENDIAN)
+  static constexpr int kLaneOffsets[16] = {15, 14, 13, 12, 11, 10, 9, 8,
+                                           7,  6,  5,  4,  3,  2,  1, 0};
+#else
+  static constexpr int kLaneOffsets[16] = {0, 1, 2,  3,  4,  5,  6,  7,
+                                           8, 9, 10, 11, 12, 13, 14, 15};
+#endif
   struct Replacement {
     Node** node = nullptr;
     SimdType type;  // represents output type