Silenced some weird (very likely false-positive) clang-tidy warnings.

source/mijin/container/optional.hpp

@@ -35,7 +35,7 @@ struct OptionalStorage
     std::uint8_t used = 0;
 
     [[nodiscard]]
-    constexpr bool empty() const noexcept { return !used; }
+    constexpr bool empty() const noexcept { return !used; } // NOLINT(clang-analyzer-core.uninitialized.UndefReturn)
 
     template<typename... TArgs>
     constexpr void emplace(TArgs&&... args) noexcept
@@ -111,7 +111,7 @@ template<typename TValue>
 class Optional
 {
 private:
-    impl::OptionalStorage<TValue> storage_;
+    impl::OptionalStorage<TValue> storage_ = {};
 public:
     constexpr Optional() = default;
     constexpr Optional(NullOptional) noexcept {}