[util] Add move-assignment operators to node_map, deque

Also add them to wait_queue as a wrapper to calling deque's
move-assignmen operator.

src/kernel/wait_queue.cpp

@@ -1,8 +1,20 @@
+#include <utility>
 #include "objects/thread.h"
 #include "wait_queue.h"
 
+wait_queue::wait_queue(wait_queue &&other) :
+    m_threads {std::move(other.m_threads)} {}
+
 wait_queue::~wait_queue() { clear(); }
 
+wait_queue &
+wait_queue::operator=(wait_queue &&other)
+{
+    clear();
+    m_threads = std::move(other.m_threads);
+    return *this;
+}
+
 void
 wait_queue::add_thread(obj::thread *t)
 {

src/kernel/wait_queue.h

@@ -12,6 +12,11 @@ namespace obj {
 class wait_queue
 {
 public:
+    wait_queue() = default;
+    wait_queue(wait_queue &&other);
+
+    wait_queue & operator=(wait_queue &&other);
+
     /// Wake all threads when destructing
     ~wait_queue();
 
@@ -28,6 +33,9 @@ public:
     /// \arg value  The value passed to thread::wake
     void clear(uint64_t value = 0);
 
+    /// Check if the queue is empty
+    bool empty() const { return m_threads.empty(); }
+
 private:
     /// Get rid of any exited threads that are next
     /// in the queue. Caller must hold the queue lock.

src/libraries/util/util/deque.h

@@ -2,6 +2,7 @@
 /// \file linked_list.h
 /// A generic templatized linked list.
 
+#include <utility>
 #include <assert.h>
 #include <string.h>
 #include <util/linked_list.h>
@@ -37,9 +38,23 @@ public:
         size_t index;
     };
 
-    deque() : m_first(0), m_next(N) {}
+    deque() : m_first {0}, m_next {N} {}
+
+    deque(deque &&other) :
+        m_first {other.m_first},
+        m_next {other.m_next},
+        m_list {std::move(other.m_list)} {}
+
     ~deque() { clear(); }
 
+    deque & operator=(deque &&other) {
+        clear();
+        m_first = other.m_first;
+        m_next = other.m_next;
+        m_list = std::move(other.m_list);
+        return *this;
+    }
+
     inline void push_front(const T& item) {
         if (!m_first) { // need a new block at the start
             node_type *n = new node_type;

src/libraries/util/util/node_map.h

@@ -150,7 +150,7 @@ public:
             key_type &key_at_slot = get_map_key(node_at_slot);
 
             if (open(key_at_slot)) {
-                node_at_slot = node;
+                node_at_slot = std::move(node);
                 if (!found)
                     inserted_at = slot;
                 return m_nodes[inserted_at];