Rollup merge of #115011 - compiler-errors:warn-on-elided-assoc-ct-lt, r=cjgillot

Warn on elided lifetimes in associated constants (`ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT`)

Elided lifetimes in associated constants (in impls) erroneously resolve to fresh lifetime parameters on the impl since #97313. This is not correct behavior (see #38831).

I originally opened #114716 to fix this, but given the time that has passed, the crater results seem pretty bad: #114716 (comment)

This PR alternatively implements a lint against this behavior, and I'm hoping to bump this to deny in a few versions.

Author: compiler-errors

crates/test-utils/src/fixture.rs

@@ -313,7 +313,7 @@ impl FixtureWithProjectMeta {
 }
 
 impl MiniCore {
-    const RAW_SOURCE: &str = include_str!("./minicore.rs");
+    const RAW_SOURCE: &'static str = include_str!("./minicore.rs");
 
     fn has_flag(&self, flag: &str) -> bool {
         self.activated_flags.iter().any(|it| it == flag)