Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Includes/libcpp/deque.pxd

Index: third_party/cython/src/Cython/Includes/libcpp/deque.pxd
diff --git a/third_party/cython/src/Cython/Includes/libcpp/deque.pxd b/third_party/cython/src/Cython/Includes/libcpp/deque.pxd
new file mode 100644
index 0000000000000000000000000000000000000000..0ade803ac740bc3b329a21ef9c41f2744005f025
--- /dev/null
+++ b/third_party/cython/src/Cython/Includes/libcpp/deque.pxd
@@ -0,0 +1,62 @@
+from pair cimport pair
+
+cdef extern from "<deque>" namespace "std":
+    cdef cppclass deque[T]:
+        cppclass iterator:
+            T& operator*() nogil
+            iterator operator++() nogil
+            iterator operator--() nogil
+            bint operator==(iterator) nogil
+            bint operator!=(iterator) nogil
+        cppclass reverse_iterator:
+            T& operator*() nogil
+            iterator operator++() nogil
+            iterator operator--() nogil
+            bint operator==(reverse_iterator) nogil
+            bint operator!=(reverse_iterator) nogil
+        #cppclass const_iterator(iterator):
+        #    pass
+        #cppclass const_reverse_iterator(reverse_iterator):
+        #    pass
+        deque() nogil except +
+        deque(deque&) nogil except +
+        deque(size_t) nogil except +
+        deque(size_t, T&) nogil except +
+        #deque[input_iterator](input_iterator, input_iterator)
+        T& operator[](size_t) nogil
+        #deque& operator=(deque&)
+        bint operator==(deque&, deque&) nogil
+        bint operator!=(deque&, deque&) nogil
+        bint operator<(deque&, deque&) nogil
+        bint operator>(deque&, deque&) nogil
+        bint operator<=(deque&, deque&) nogil
+        bint operator>=(deque&, deque&) nogil
+        void assign(size_t, T&) nogil
+        void assign(input_iterator, input_iterator) nogil
+        T& at(size_t) nogil
+        T& back() nogil
+        iterator begin() nogil
+        #const_iterator begin()
+        void clear() nogil
+        bint empty() nogil
+        iterator end() nogil
+        #const_iterator end()
+        iterator erase(iterator) nogil
+        iterator erase(iterator, iterator) nogil
+        T& front() nogil
+        iterator insert(iterator, T&) nogil
+        void insert(iterator, size_t, T&) nogil
+        void insert(iterator, input_iterator, input_iterator) nogil
+        size_t max_size() nogil
+        void pop_back() nogil
+        void pop_front() nogil
+        void push_back(T&) nogil
+        void push_front(T&) nogil
+        reverse_iterator rbegin() nogil
+        #const_reverse_iterator rbegin()
+        reverse_iterator rend() nogil
+        #const_reverse_iterator rend()
+        void resize(size_t) nogil
+        void resize(size_t, T&) nogil
+        size_t size() nogil
+        void swap(deque&) nogil