Partial 3.8 async "for" fixes

uncompyle6/parsers/parse37base.py

@@ -584,6 +584,21 @@ class Python37BaseParser(PythonParser):
                 """
                 self.add_unique_doc_rules(rules_str, customize)
 
+            elif opname == "GET_ANEXT":
+                self.addRule(
+                    """
+                    func_async_prefix   ::= _come_froms SETUP_FINALLY GET_ANEXT LOAD_CONST YIELD_FROM POP_BLOCK
+                    func_async_middle   ::= JUMP_FORWARD COME_FROM_EXCEPT
+                                            DUP_TOP LOAD_GLOBAL COMPARE_OP POP_JUMP_IF_TRUE
+                    list_afor2          ::= func_async_prefix
+                                            store list_iter
+                                            JUMP_BACK COME_FROM_FINALLY
+                                            END_ASYNC_FOR
+                   """,
+                    nop_func,
+                )
+                custom_ops_processed.add(opname)
+
             elif opname == "FORMAT_VALUE_ATTR":
                 rules_str = """
                 expr              ::= formatted_value2

uncompyle6/parsers/parse38.py

@@ -75,6 +75,11 @@ class Python38Parser(Python37Parser):
                                COME_FROM_FINALLY
                                END_ASYNC_FOR
 
+       genexpr_func_async  ::= LOAD_FAST func_async_prefix
+                               store comp_iter
+                               JUMP_BACK COME_FROM_FINALLY
+                               END_ASYNC_FOR
+
         # FIXME: come froms after the else_suite or END_ASYNC_FOR distinguish which of
         # for / forelse is used. Add come froms and check of add up control-flow detection phase.
         async_forelse_stmt38 ::= expr