Add basic character device support. Start with null and zero.

VirtualFileSystem/NullDevice.cpp

@@ -0,0 +1,25 @@
+#include "NullDevice.h"
+#include "Limits.h"
+#include <AK/StdLib.h>
+#include <cstring>
+#include <cstdio>
+
+NullDevice::NullDevice()
+{
+}
+
+NullDevice::~NullDevice()
+{
+}
+
+ssize_t NullDevice::read(byte*, size_t)
+{
+    printf("read from null\n");
+    return 0;
+}
+
+ssize_t NullDevice::write(const byte*, size_t bufferSize)
+{
+    return min(GoodBufferSize, bufferSize);
+}
+