[async-iteration] implement Async-from-Sync Iterator

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index 9f172f98cff20b7d4e3c63d52dde5a17c4ef3b92..9fc1327e245af1f494f6fa97ffb6903ec85a2c6e 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -196,11 +196,14 @@ enum ContextLookupFlags {
   V(ARRAY_BUFFER_FUN_INDEX, JSFunction, array_buffer_fun)                      \
   V(ARRAY_BUFFER_MAP_INDEX, Map, array_buffer_map)                             \
   V(ARRAY_FUNCTION_INDEX, JSFunction, array_function)                          \
+  V(ASYNC_FROM_SYNC_ITERATOR_MAP_INDEX, Map, async_from_sync_iterator_map)     \
   V(ASYNC_FUNCTION_AWAIT_REJECT_SHARED_FUN, SharedFunctionInfo,                \
     async_function_await_reject_shared_fun)                                    \
   V(ASYNC_FUNCTION_AWAIT_RESOLVE_SHARED_FUN, SharedFunctionInfo,               \
     async_function_await_resolve_shared_fun)                                   \
   V(ASYNC_FUNCTION_FUNCTION_INDEX, JSFunction, async_function_constructor)     \
+  V(ASYNC_ITERATOR_VALUE_UNWRAP_SHARED_FUN, SharedFunctionInfo,                \
+    async_iterator_value_unwrap_shared_fun)                                    \
   V(BOOL16X8_FUNCTION_INDEX, JSFunction, bool16x8_function)                    \
   V(BOOL32X4_FUNCTION_INDEX, JSFunction, bool32x4_function)                    \
   V(BOOL8X16_FUNCTION_INDEX, JSFunction, bool8x16_function)                    \