`StaticVector`: Replace `std::aligned_storage_t`

`std::aligned_*` are deprecated in C++23 per
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1413r3.pdf

Source/utils/static_vector.hpp

@@ -1,12 +1,11 @@
 #pragma once
 
-#include <cstddef>
 #include <initializer_list>
 #include <memory>
-#include <type_traits>
 #include <utility>
 
 #include "appfat.h"
+#include "utils/stdcompat/cstddef.hpp"
 
 namespace devilution {
 
@@ -58,47 +57,53 @@ public:
 	T &emplace_back(Args &&...args) // NOLINT(readability-identifier-naming)
 	{
 		assert(size_ < N);
-		::new (&data_[size_]) T(std::forward<Args>(args)...);
-#if __cplusplus >= 201703L
-		T &result = *std::launder(reinterpret_cast<T *>(&data_[size_]));
-#else
-		T &result = *reinterpret_cast<T *>(&data_[size_]);
-#endif
-		++size_;
-		return result;
+		return *::new (&data_[size_++]) T(std::forward<Args>(args)...);
 	}
 
 	T &operator[](std::size_t pos)
 	{
-#if __cplusplus >= 201703L
-		return *std::launder(reinterpret_cast<T *>(&data_[pos]));
-#else
-		return *reinterpret_cast<T *>(&data_[pos]);
-#endif
+		return *data_[pos].ptr();
 	}
 
 	const T &operator[](std::size_t pos) const
 	{
-#if __cplusplus >= 201703L
-		return *std::launder(reinterpret_cast<const T *>(&data_[pos]));
-#else
-		return *reinterpret_cast<const T *>(&data_[pos]);
-#endif
+		return *data_[pos].ptr();
 	}
 
 	~StaticVector()
 	{
 		for (std::size_t pos = 0; pos < size_; ++pos) {
 #if __cplusplus >= 201703L
-			std::destroy_at(std::launder(reinterpret_cast<T *>(&data_[pos])));
+			std::destroy_at(data_[pos].ptr());
 #else
-			reinterpret_cast<T *>(&data_[pos])->~T();
+			data_[pos].ptr()->~T();
 #endif
 		}
 	}
 
 private:
-	std::aligned_storage_t<sizeof(T), alignof(T)> data_[N];
+	struct AlignedStorage {
+		alignas(alignof(T)) byte data[sizeof(T)];
+
+		const T *ptr() const
+		{
+#if __cplusplus >= 201703L
+			return std::launder(reinterpret_cast<const T *>(data));
+#else
+			return reinterpret_cast<const T *>(data);
+#endif
+		}
+
+		T *ptr()
+		{
+#if __cplusplus >= 201703L
+			return std::launder(reinterpret_cast<T *>(data));
+#else
+			return reinterpret_cast<T *>(data);
+#endif
+		}
+	};
+	AlignedStorage data_[N];
 	std::size_t size_ = 0;
 };