Kernel: Implement very simple kernel module loading

It's now possible to load a .o file into the kernel via a syscall.
The kernel will perform all the necessary ELF relocations, and then
call the "module_init" symbol in the loaded module.

Kernel/TestModule.cpp

@@ -0,0 +1,12 @@
+#include <Kernel/kstdio.h>
+
+extern "C" void outside_func();
+
+extern "C" void module_init()
+{
+    kprintf("TestModule has booted!\n");
+
+    for (int i = 0; i < 99; ++i) {
+        kprintf("i is now %d\n", i);
+    }
+}