Spellchecking compiler code

Address some spelling mistakes in strings, private function names, and function params.

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -683,7 +683,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                         && is_new_pred
                     {
                         debug!(
-                            "evaluate_nested_obligations: adding projection predicate\
+                            "evaluate_nested_obligations: adding projection predicate \
                             to computed_preds: {:?}",
                             predicate
                         );