Add a kmalloc_eternal() for things that will never be destroyed.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/9a086b2d358

VirtualFileSystem/VirtualFileSystem.h

@@ -28,6 +28,7 @@ inline constexpr dword encodedDevice(unsigned major, unsigned minor)
 }
 
 class VirtualFileSystem {
+    AK_MAKE_ETERNAL
 public:
     static void initializeGlobals();
     static SpinLock& lock();