add setupval/getupval

readthedocs/lua_bytecode_reference.rst

@@ -1343,8 +1343,8 @@ The ``TFORLOOP`` insruction executes and checks whether ``i`` is ``nil``. If it
 The body of the generic ``for`` loop executes (``print(i,v)``) and then ``TFORCALL`` is encountered again, calling the iterator function to get the next iteration state. Finally, when the ``TFORLOOP`` finds that the first result from the iterator is ``nil``, the loop ends, and execution continues on line [11].
 
 
-GETUPVAL and SETUPVAL instructions
-==================================
+OP_GETUPVAL and OP_SETUPVAL instructions
+========================================
 
 Syntax
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