Rollup merge of #148370 - estebank:outer-param, r=JonathanBrouwer

Point at inner item when it uses generic type param from outer item or `Self`

Partially address rust-lang/rust#37892.

In E0401 generated in resolve:
```
error[E0401]: can't use generic parameters from outer item
  --> $DIR/E0401.rs:4:39
   |
LL | fn foo<T>(x: T) {
   |        - type parameter from outer item
LL |     fn bfnr<U, V: Baz<U>, W: Fn()>(y: T) {
   |        ----                           ^ use of generic parameter from outer item
   |        |
   |        generic parameter used in this inner function
   |
help: try introducing a local generic parameter here
   |
LL |     fn bfnr<T, U, V: Baz<U>, W: Fn()>(y: T) {
   |             ++
```
In E0401 generated in hir_typeck:
```
error[E0401]: can't reference `Self` constructor from outer item
  --> $DIR/do-not-ice-on-note_and_explain.rs:6:13
   |
LL | impl<B> A<B> {
   | ------------ the inner item doesn't inherit generics from this impl, so `Self` is invalid to reference
LL |     fn d() {
LL |         fn d() {
   |            - `Self` used in this inner item
LL |             Self(1)
   |             ^^^^ help: replace `Self` with the actual type: `A`
```

Author: Zalathar