re-add accidentally removed line

Author: TimNN

src/librustc_typeck/check/wfcheck.rs

@@ -480,6 +480,7 @@ impl<'ccx, 'gcx> CheckTypeWellFormedVisitor<'ccx, 'gcx> {
                 (ast_generics.lifetimes[index].lifetime.span,
                  ast_generics.lifetimes[index].lifetime.name)
             } else {
+                let index = index - ast_generics.lifetimes.len();
                 (ast_generics.ty_params[index].span,
                  ast_generics.ty_params[index].name)
             };

src/test/compile-fail/issue-36299.rs

@@ -0,0 +1,15 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+struct Foo<'a, A> {}
+//~^ ERROR parameter `'a` is never used
+//~| ERROR parameter `A` is never used
+
+fn main() {}