Adding a disabled debug helper.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32217 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/arch/x86/arch_vm_translation_map.cpp

@@ -192,6 +192,15 @@ vm_translation_map_arch_info::Delete()
 	sTMapList.Remove(this);
 	locker.Unlock();
 
+#if 0
+	// this sanity check can be enabled when corruption due to
+	// overwriting an active page directory is suspected
+	addr_t activePageDirectory;
+	read_cr3(activePageDirectory);
+	if (activePageDirectory == (addr_t)pgdir_phys)
+		panic("deleting a still active page directory\n");
+#endif
+
 	if (are_interrupts_enabled())
 		delete this;
 	else