Memory: move GetPhysicalPointer and IsValidPhysicalAddress into class

src/core/hle/kernel/kernel.h

@@ -46,6 +46,7 @@ class SharedMemory;
 class ThreadManager;
 class TimerManager;
 class VMManager;
+struct AddressMapping;
 
 enum class ResetType {
     OneShot,
@@ -216,6 +217,8 @@ public:
 
     MemoryRegionInfo* GetMemoryRegion(MemoryRegion region);
 
+    void HandleSpecialMapping(VMManager& address_space, const AddressMapping& mapping);
+
     std::array<MemoryRegionInfo, 3> memory_regions;
 
     /// Adds a port to the named port table