main: Log host system memory parameters

Logs both physical memory and swapfile sizes, this is useful for support.

src/common/memory_detect.h

@@ -0,0 +1,22 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+namespace Common {
+
+struct MemoryInfo {
+    u64 TotalPhysicalMemory{};
+    u64 TotalSwapMemory{};
+};
+
+/**
+ * Gets the memory info of the host system
+ * @return Reference to a MemoryInfo struct with the physical and swap memory sizes in bytes
+ */
+const MemoryInfo& GetMemInfo();
+
+} // namespace Common