Special case detecting 'static lifetime requirement coming from -> Box<dyn Trait>

[estebank]

error[E0310]: the parameter type `R` may not live long enough
  --> $DIR/implicit-static-lifetime-in-dyn-trait-return-type.rs:10:5
   |
LL | fn bb<R>(r: R) -> Box<dyn Foo> {
   |                       ------- this `dyn Trait` has an implicit `'static` lifetime bound
LL |     Box::new(Bar(r))
   |     ^^^^^^^^^^^^^^^^
   |     |
   |     the parameter type `R` must be valid for the static lifetime...
   |     ...so that the type `R` will meet its required lifetime bounds
   |
help: consider adding an explicit lifetime bound
   |
LL | fn bb<R: 'static>(r: R) -> Box<dyn Foo> {
   |        +++++++++

Partly address #41966 and #54753. #103849, which shows a case where there's an intermediary binding, is not addressed at all, as aren't cases other than Box<dyn Trait> return type.

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