message: traverse if-then-else expr when checking deps
diff: @@ -190,6 +190,11 @@ fn term_deps(
  term_deps(body_expr, item_names, local_names, deps);
  pop_pattern(pattern, local_names);
  }
  + Term::If(_, cond_expr, then_expr, else_expr) => {
  + term_deps(cond_expr, item_names, local_names, deps);
  + term_deps(then_expr, item_names, local_names, deps);
  + term_deps(else_expr, item_names, local_names, deps);
  + }
  Term::Match(_, scrutinee, equations) => {
  let initial_locals_names_len = local_names.len();
  term_deps(scrutinee, item_names, local_names, deps);
  @@ -269,7 +274,6 @@ fn term_deps(
  | Term::NumberLiteral(_, _)
  | Term::BooleanLiteral(_, _)
  | Term::ReportedError(_) => {}
  - Term::If(_, _, _, _) => todo!(),
  }
  }
  