Experimental squashing of reservation memory area.

Enables trivial synchronization between shared mem.
Reduces memory usage, but potentially degrades performance.
Rename an overload of vm::passive_lock to vm::range_lock.

Utilities/VirtualMemory.h

@@ -48,9 +48,10 @@ namespace utils
 		int m_file;
 #endif
 		u32 m_size;
+		u32 m_flags;
 
 	public:
-		explicit shm(u32 size);
+		explicit shm(u32 size, u32 flags = 0);
 
 		shm(const shm&) = delete;
 
@@ -74,5 +75,11 @@ namespace utils
 		{
 			return m_size;
 		}
+
+		// Flags are unspecified, consider it userdata
+		u32 flags() const
+		{
+			return m_flags;
+		}
 	};
 }