message: Avoid using overly restrictive references
diff: @@ -179,12 +179,12 @@ impl<'arena> Context<'arena> {
  semantics::EvalContext::new(&mut self.rigid_exprs, &self.flexible_exprs)
  }
  - pub fn elim_context<'this>(&'this mut self) -> semantics::ElimContext<'arena, 'this> {
  + pub fn elim_context<'this>(&'this self) -> semantics::ElimContext<'arena, 'this> {
  semantics::ElimContext::new(&self.flexible_exprs)
  }
  pub fn quote_context<'out_arena>(
  - &mut self,
  + &self,
  scope: &'out_arena Scope<'out_arena>,
  ) -> semantics::QuoteContext<'arena, 'out_arena, '_> {
  semantics::QuoteContext::new(scope, self.rigid_exprs.len(), &self.flexible_exprs)
  