Rollup merge of rust-lang#129207 - GrigorenkoPV:elided-is-named, r=cjgillot

Lint that warns when an elided lifetime ends up being a named lifetime

As suggested in rust-lang#48686 (comment)

Fixes rust-lang#48686

Author: matthiaskrgr

tests/ui/needless_lifetimes.stderr

@@ -1,3 +1,14 @@
+error: elided lifetime has a name
+  --> tests/ui/needless_lifetimes.rs:266:52
+   |
+LL | fn named_input_elided_output<'a>(_arg: &'a str) -> &str {
+   |                              --                    ^ this elided lifetime gets resolved as `'a`
+   |                              |
+   |                              lifetime `'a` declared here
+   |
+   = note: `-D elided-named-lifetimes` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(elided_named_lifetimes)]`
+
 error: the following explicit lifetimes could be elided: 'a, 'b
   --> tests/ui/needless_lifetimes.rs:17:23
    |
@@ -553,5 +564,5 @@ LL -         fn one_input<'a>(x: &'a u8) -> &'a u8 {
 LL +         fn one_input(x: &u8) -> &u8 {
    |
 
-error: aborting due to 46 previous errors
+error: aborting due to 47 previous errors
 

tests/ui/ptr_arg.stderr

@@ -1,3 +1,12 @@
+error: elided lifetime has a name
+  --> tests/ui/ptr_arg.rs:295:56
+   |
+LL |     fn cow_good_ret_ty<'a>(input: &'a Cow<'a, str>) -> &str {
+   |                        -- lifetime `'a` declared here  ^ this elided lifetime gets resolved as `'a`
+   |
+   = note: `-D elided-named-lifetimes` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(elided_named_lifetimes)]`
+
 error: writing `&Vec` instead of `&[_]` involves a new object where a slice will do
   --> tests/ui/ptr_arg.rs:13:14
    |
@@ -212,5 +221,5 @@ error: using a reference to `Cow` is not recommended
 LL |     fn cow_bad_ret_ty_2<'a, 'b>(input: &'a Cow<'a, str>) -> &'b str {
    |                                        ^^^^^^^^^^^^^^^^ help: change this to: `&str`
 
-error: aborting due to 24 previous errors
+error: aborting due to 25 previous errors