Function rewrite_query 

pub fn rewrite_query(q: &Query, now_ms: i64) -> Query

Rewrite every row function in a parsed query to a $self method call, root every string literal compared with a path intrinsic, and fold the dates over literals (fold_dates, at now_ms) — one transform over the AST (spec/oqx/AST.md §5), every block included.