LustreDesugarLastDesugars the last operator (only allowed within frame blocks).
val error_message : error_kind -> stringval desugar_last : LustreAst.t -> (LustreAst.t, [> error ]) Stdlib.resultReplaces each last x occurring in a frame block with a fresh local variable initialized by the frame and equal to pre x afterwards. Returns an error if last is used outside of a frame block, or if it is applied to an input of the node.