LibJS: Add Handle::operator->()

Userland/Libraries/LibJS/Heap/Handle.h

@@ -53,6 +53,9 @@ public:
 
     bool is_null() const { return m_impl.is_null(); }
 
+    T* operator->() { return cell(); }
+    T const* operator->() const { return cell(); }
+
 private:
     explicit Handle(NonnullRefPtr<HandleImpl> impl)
         : m_impl(move(impl))

Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp

@@ -388,7 +388,7 @@ ThrowCompletionOr<BalancedDuration> balance_duration(GlobalObject& global_object
         days = result.days;
 
         // c. Set nanoseconds to result.[[Nanoseconds]].
-        total_nanoseconds = result.nanoseconds.cell()->big_integer();
+        total_nanoseconds = result.nanoseconds->big_integer();
     }
     // 5. Else,
     else {
@@ -1238,7 +1238,7 @@ ThrowCompletionOr<RoundedDuration> round_duration(GlobalObject& global_object, d
         auto result = TRY(nanoseconds_to_days(global_object, *nanoseconds_bigint, intermediate));
 
         // e. Set days to days + result.[[Days]] + result.[[Nanoseconds]] / result.[[DayLength]].
-        auto nanoseconds_division_result = result.nanoseconds.cell()->big_integer().divided_by(Crypto::UnsignedBigInteger::create_from((u64)result.day_length));
+        auto nanoseconds_division_result = result.nanoseconds->big_integer().divided_by(Crypto::UnsignedBigInteger::create_from((u64)result.day_length));
         days += result.days + nanoseconds_division_result.quotient.to_double() + nanoseconds_division_result.remainder.to_double() / result.day_length;
 
         // f. Set hours, minutes, seconds, milliseconds, microseconds, and nanoseconds to 0.