Saveload: Add span overloads to ReadBuffer and MemoryDumper

src/sl/saveload_buffer.h

@@ -125,6 +125,11 @@ struct ReadBuffer {
 		}
 	}
 
+	inline void CopyBytes(std::span<byte> buffer)
+	{
+		this->CopyBytes(buffer.data(), buffer.size());
+	}
+
 	/**
 	 * Get the size of the memory dump made so far.
 	 * @return The size.
@@ -209,6 +214,11 @@ struct MemoryDumper {
 		}
 	}
 
+	inline void CopyBytes(std::span<const byte> buffer)
+	{
+		this->CopyBytes(buffer.data(), buffer.size());
+	}
+
 	inline void RawWriteByte(byte b)
 	{
 		*this->buf++ = b;