add opcodes to pickle stubs (#1321)

stdlib/3/pickle.pyi

@@ -1,5 +1,4 @@
-# Stubs for pickle
-
+import sys
 from typing import Any, IO, Union, Tuple, Callable, Optional, Iterator
 # Imports used in type comments only.
 from typing import Mapping  # noqa
@@ -65,3 +64,76 @@ class Unpickler:
     def persistent_load(self, pid: Any) -> Any: ...
 
     def find_class(self, module: str, name: str) -> Any: ...
+
+MARK: bytes
+STOP: bytes
+POP: bytes
+POP_MARK: bytes
+DUP: bytes
+FLOAT: bytes
+INT: bytes
+BININT: bytes
+BININT1: bytes
+LONG: bytes
+BININT2: bytes
+NONE: bytes
+PERSID: bytes
+BINPERSID: bytes
+REDUCE: bytes
+STRING: bytes
+BINSTRING: bytes
+SHORT_BINSTRING: bytes
+UNICODE: bytes
+BINUNICODE: bytes
+APPEND: bytes
+BUILD: bytes
+GLOBAL: bytes
+DICT: bytes
+EMPTY_DICT: bytes
+APPENDS: bytes
+GET: bytes
+BINGET: bytes
+INST: bytes
+LONG_BINGET: bytes
+LIST: bytes
+EMPTY_LIST: bytes
+OBJ: bytes
+PUT: bytes
+BINPUT: bytes
+LONG_BINPUT: bytes
+SETITEM: bytes
+TUPLE: bytes
+EMPTY_TUPLE: bytes
+SETITEMS: bytes
+BINFLOAT: bytes
+
+TRUE: bytes
+FALSE: bytes
+
+PROTO: bytes
+NEWOBJ: bytes
+EXT1: bytes
+EXT2: bytes
+EXT4: bytes
+TUPLE1: bytes
+TUPLE2: bytes
+TUPLE3: bytes
+NEWTRUE: bytes
+NEWFALSE: bytes
+LONG1: bytes
+LONG4: bytes
+
+BINBYTES: bytes
+SHORT_BINBYTES: bytes
+
+if sys.version_info >= (3, 4):
+    SHORT_BINUNICODE: bytes
+    BINUNICODE8: bytes
+    BINBYTES8: bytes
+    EMPTY_SET: bytes
+    ADDITEMS: bytes
+    FROZENSET: bytes
+    NEWOBJ_EX: bytes
+    STACK_GLOBAL: bytes
+    MEMOIZE: bytes
+    FRAME: bytes