Make hitting the recursion limit in projection non-fatal

This is relied on by wundergraph.

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -291,10 +291,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         self.infcx.tcx
     }
 
-    pub(super) fn query_mode(&self) -> TraitQueryMode {
-        self.query_mode
-    }
-
     ///////////////////////////////////////////////////////////////////////////
     // Selection
     //