[wasm-simd][scalar-lowering] Fix 64x2 load splat

64x2 nodes were already supported, we just didn't add the case for
64x2 load splat. Add that in and we pass simd_load_splat.js.

Bug: v8:10507
Change-Id: If9145e1b3a4595f4707ca0fc3dcee466773c054f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2432074Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70149}

src/compiler/simd-scalar-lowering.cc

@@ -360,6 +360,9 @@ void SimdScalarLowering::SetLoweredType(Node* node, Node* output) {
         case LoadTransformation::kS32x4LoadSplat:
           replacements_[node->id()].type = SimdType::kInt32x4;
           break;
+        case LoadTransformation::kS64x2LoadSplat:
+          replacements_[node->id()].type = SimdType::kInt64x2;
+          break;
         case LoadTransformation::kI16x8Load8x8S:
         case LoadTransformation::kI16x8Load8x8U:
           replacements_[node->id()].type = SimdType::kInt16x8;
@@ -587,6 +590,7 @@ void SimdScalarLowering::LowerLoadTransformOp(Node* node, SimdType type) {
     case LoadTransformation::kS8x16LoadSplat:
     case LoadTransformation::kS16x8LoadSplat:
     case LoadTransformation::kS32x4LoadSplat:
+    case LoadTransformation::kS64x2LoadSplat:
       load_rep = MachineTypeFrom(type);
       break;
     default:

test/wasm-spec-tests/wasm-spec-tests.status

@@ -42,7 +42,6 @@
   # we finish the implementation, see v8:10507.
   'proposals/simd/simd_conversions' : [PASS, FAIL],
   'proposals/simd/simd_lane' : [PASS, FAIL],
-  'proposals/simd/simd_load_splat' : [PASS, FAIL],
 
 }],  # ALWAYS