[wasm] Big endian support for simd lowering for I32x4AddHoriz

Change-Id: Idad7f62ca0dcec5ceec33e8d517f05351cacc012
Reviewed-on: https://chromium-review.googlesource.com/915064Reviewed-by: Aseem Garg <aseemgarg@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Cr-Commit-Position: refs/heads/master@{#51284}

src/compiler/simd-scalar-lowering.cc

@@ -401,9 +401,16 @@ void SimdScalarLowering::LowerBinaryOp(Node* node, SimdType input_rep_type,
     }
   } else {
     for (int i = 0; i < num_lanes / 2; ++i) {
+#if defined(V8_TARGET_BIG_ENDIAN)
+      rep_node[i] =
+          graph()->NewNode(op, rep_right[i * 2], rep_right[i * 2 + 1]);
+      rep_node[i + num_lanes / 2] =
+          graph()->NewNode(op, rep_left[i * 2], rep_left[i * 2 + 1]);
+#else
       rep_node[i] = graph()->NewNode(op, rep_left[i * 2], rep_left[i * 2 + 1]);
       rep_node[i + num_lanes / 2] =
           graph()->NewNode(op, rep_right[i * 2], rep_right[i * 2 + 1]);
+#endif
     }
   }
   ReplaceNode(node, rep_node, num_lanes);

test/cctest/cctest.status

@@ -333,7 +333,6 @@
   'test-run-wasm-simd/RunWasm_S32x4NonCanonicalSelect_compiled': [SKIP],
   'test-run-wasm-simd/RunWasm_S16x8NonCanonicalSelect_compiled': [SKIP],
   'test-run-wasm-simd/RunWasm_S8x16NonCanonicalSelect_compiled': [SKIP],
-  'test-run-wasm-simd/RunWasm_I32x4AddHoriz_compiled': [SKIP],
   'test-run-wasm-simd/RunWasm_I16x8AddHoriz_compiled': [SKIP],
   'test-run-wasm-simd/RunWasm_F32x4AddHoriz_compiled': [SKIP],
   'test-run-wasm-simd/RunWasm_S32x4Dup_compiled': [SKIP],