UI test: "elided" has just the one 'l'; exercise underscore lifetime

The files were named 'ellided-lifetimes', but the word "elided" only has
one 'l' (see, e.g., https://en.wiktionary.org/wiki/elide). We add a
couple lines to the test that exercise underscore lifetimes with the
elided-lifetimes-in-paths lint: in the current implementation, the lint
fires (as one can see in the expectation file), but it really shouldn't
(notice that the message says to use an underscore lifetime!); this is
to be fixed in another commit.

src/test/ui/in-band-lifetimes/ellided-lifetimes.rs → src/test/ui/in-band-lifetimes/elided-lifetimes.rs

@@ -7,13 +7,18 @@
 // <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.
-#![allow(warnings)]
-#![allow(unused_variables, dead_code, unused, bad_style)]
+
+#![allow(unused)]
 #![deny(elided_lifetimes_in_paths)]
 
 struct Foo<'a> { x: &'a u32 }
+
 fn foo(x: &Foo) {
     //~^ ERROR: hidden lifetime parameters are deprecated, try `Foo<'_>`
 }
 
+fn bar(x: &Foo<'_>) {
+    //~^ ERROR: hidden lifetime parameters are deprecated, try `Foo<'_>`
+}
+
 fn main() {}

src/test/ui/in-band-lifetimes/elided-lifetimes.stderr

@@ -0,0 +1,20 @@
+error: hidden lifetime parameters are deprecated, try `Foo<'_>`
+  --> $DIR/elided-lifetimes.rs:16:12
+   |
+LL | fn foo(x: &Foo) {
+   |            ^^^
+   |
+note: lint level defined here
+  --> $DIR/elided-lifetimes.rs:12:9
+   |
+LL | #![deny(elided_lifetimes_in_paths)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: hidden lifetime parameters are deprecated, try `Foo<'_>`
+  --> $DIR/elided-lifetimes.rs:20:16
+   |
+LL | fn bar(x: &Foo<'_>) {
+   |                ^^
+
+error: aborting due to 2 previous errors
+