[interpreter] Add support for scalable operands.

src/interpreter/constant-array-builder.cc

Index: src/interpreter/constant-array-builder.cc
diff --git a/src/interpreter/constant-array-builder.cc b/src/interpreter/constant-array-builder.cc
index 018fda23e29e90e87a76e149f92e2c07caccea0f..c8330996aa0ffb307e653bff88a8c9ae4e48c40b 100644
--- a/src/interpreter/constant-array-builder.cc
+++ b/src/interpreter/constant-array-builder.cc
@@ -58,6 +58,8 @@ ConstantArrayBuilder::ConstantArrayBuilder(Isolate* isolate, Zone* zone)
       new (zone) ConstantArraySlice(zone, 0, k8BitCapacity, OperandSize::kByte);
   idx_slice_[1] = new (zone) ConstantArraySlice(
       zone, k8BitCapacity, k16BitCapacity, OperandSize::kShort);
+  idx_slice_[2] = new (zone) ConstantArraySlice(
+      zone, k8BitCapacity, k16BitCapacity, OperandSize::kQuad);
 }
 
 size_t ConstantArrayBuilder::size() const {
@@ -164,6 +166,9 @@ ConstantArrayBuilder::OperandSizeToSlice(OperandSize operand_size) const {
     case OperandSize::kShort:
       slice = idx_slice_[1];
       break;
+    case OperandSize::kQuad:
+      slice = idx_slice_[2];
+      break;
   }
   DCHECK(slice->operand_size() == operand_size);
   return slice;