Rollup merge of #40734 - adamransom:fix/40661, r=jseyfried

Add warning for use of lifetime parameter with 'static bound

Previously a `'static` lifetime bound would result in an `undeclared lifetime` error when compiling, even though it could be considered valid.

However, it is unnecessary to use it as a lifetime bound so we present the user with a warning instead and suggest using the `'static` lifetime directly, in place of the lifetime parameter. We can change this to an error (or warning with lint) if that's decided to be more appropriate.

Example output:
```
warning: unnecessary lifetime parameter `'a`
 --> ../static-lifetime-bound.rs:3:10
  |
3 | fn f<'a: 'static>(val: &'a i32) {
  |      ^^^^^^^^^^^
  |
  = help: you can use the `'static` lifetime directly, in place `'a`
```

Fixes #40661

r? @jseyfried

0 files changed, 0 insertions, 0 deletions