Fix save-analysis generation panic with invalid tuple access

src/librustc_save_analysis/dump_visitor.rs

@@ -1675,7 +1675,10 @@ impl<'l, 'tcx: 'l, 'll, O: DumpOutput + 'll> Visitor<'l> for DumpVisitor<'l, 'tc
                         }
                     }
                     ty::TyTuple(..) => {}
-                    _ => span_bug!(ex.span, "Expected struct or tuple type, found {:?}", ty),
+                    _ => {
+                        debug!("Expected struct or tuple type, found {:?}", ty);
+                        return;
+                    }
                 }
             }
             ast::ExprKind::Closure(_, _, ref decl, ref body, _fn_decl_span) => {

src/test/run-make/save-analysis-fail/foo.rs

@@ -459,3 +459,7 @@ struct Rls699 {
 fn new(f: u32) -> Rls699 {
     Rls699 { fs }
 }
+
+fn invalid_tuple_struct_access() {
+    bar.0;
+}