instr: make usage of BinaryOp enum be backward compatible

Author: MatthieuDartiailh

src/bytecode/instr.py

@@ -985,10 +985,13 @@ def _check_arg(self, name: str, opcode: int, arg: InstrArg) -> None:
 
         elif opcode in BINARY_OPS:
             if not isinstance(arg, BinaryOp):
-                raise TypeError(
-                    "operation %s argument type must be "
-                    "BinaryOp, got %s" % (name, type(arg).__name__)
-                )
+                try:
+                    arg = BinaryOp(arg)
+                except Exception as e:
+                    raise TypeError(
+                        "operation %s argument type must be "
+                        "coercible to BinaryOp, got %s" % (name, type(arg).__name__)
+                    ) from e
 
         # We do not enforce constant immortality since which constants are
         # immortal may differ between recompilation and execution.

tests/test_instr.py

@@ -167,7 +167,8 @@ def test_invalid_arg(self):
             assert name == "BINARY_OP", f"expected BINARY_OP but got {name=}"
             if PY314:
                 Instr(name, BinaryOp.SUBSCR)
-                self.assertRaises(TypeError, Instr, name, BinaryOp.SUBSCR.value)
+                Instr(name, BinaryOp.SUBSCR.value)
+                self.assertRaises(TypeError, Instr, name, "")
 
         for name in (opcode.opname[op] for op in SPECIAL_OPS):
             assert name == "LOAD_SPECIAL", f"expected LOAD_SPECIAL but got {name=}"