Fix UAF when deleting hook while in hook callback #1127 (#1130)

* Handle the cpu context save in a more pythonic way, so the context can be serialized and reuse in an other process using the same emulator architecture and modes

* Fix type error ; mistakes a size_t uint64_t ; breaks in 32bit...

* Fix the UAF situation when deleting a hook while being in a hook callback. Added an attribute 'to_delete' to hooks, and a list hooks_to_del to delay the free of the hooks

* Minor fixes ; forgot return type of clear_deleted_hooks ; do not declare variable in for predicate

list.c

@@ -90,3 +90,22 @@ bool list_remove(struct list *list, void *data)
     }
     return false;
 }
+
+// returns true if the data exists in the list
+bool list_exists(struct list *list, void *data)
+{
+    struct list_item *next, *cur = NULL;
+    // is list empty?
+    if (list->head == NULL) {
+        return false;
+    }
+    cur = list->head;
+    while (cur != NULL) {
+        next = cur->next;
+        if (cur->data == data) {
+            return true;
+        }
+        cur = next;
+    }
+    return false;
+}