Fix Instruction -> Statement backward compatibility

pymbolic/imperative/instruction.py

@@ -28,5 +28,5 @@ from warnings import warn
 warn("pymbolic.imperative.instruction was imported. This has been renamed "
         "to pymbolic.imperative.statement", DeprecationWarning, stacklevel=1)
 
-from pymbolic.imperative.instruction import (  # noqa: F401
+from pymbolic.imperative.statement import (  # noqa: F401
         Instruction, ConditionalInstruction, Assignment, Nop)