Kernel: Add initial basic support for KASAN

This commit adds minimal support for compiler-instrumentation based
memory access sanitization.
Currently we only support detection of kmalloc redzone accesses, and
kmalloc use-after-free accesses.

Support for inline checks (for improved performance), and for stack
use-after-return and use-after-return detection is left for future PRs.

Kernel/Memory/MemoryManager.h

@@ -243,6 +243,10 @@ private:
     void initialize_physical_pages();
     void register_reserved_ranges();
 
+#ifdef HAS_ADDRESS_SANITIZER
+    void initialize_kasan_shadow_memory();
+#endif
+
     void unregister_kernel_region(Region&);
 
     void protect_kernel_image();