vm: add map_self() method to utils::shm

Add complementary unmap_self() method.
Move VirtualMemory to util/vm.hpp
Minor associated include cleanup.
Move asm.h to util/asm.hpp

Utilities/Thread.cpp

@@ -73,6 +73,7 @@
 #endif
 
 #include "sync.h"
+#include "util/vm.hpp"
 #include "util/logs.hpp"
 #include "Emu/Memory/vm_locking.h"