Rollup merge of #139124 - xtexx:gh-139082, r=compiler-errors

compiler: report error when trait object type param reference self

Fixes #139082.

Emits an error when `Self` is found in the projection bounds of a trait
object. In type aliases, `Self` has no meaning, so `type A = &'static
dyn B` where `trait B = Fn() -> Self` will expands to `type A = &'static
Fn() -> Self` which is illegal, causing the region solver to bail out
when hitting the uninferred Self.

r? ````@compiler-errors```` ````@fee1-dead````

Author: Zalathar