RFR: 8357653: Inner classes of type parameters emitted as raw types in signatures [v17]

[Aggelos Biboudis]

> There are various occasions that the qualifier of an _inner type_ needs to be normalized. 
> 
> Briefly:
> 
> - This occurs when there is an explicit type application in the signature of the method or a type application operation or when type checking an expression operation (e.g., `G.Getter` in the first example, `M.B<?>` in the second example). 
> - The reference to an inner type may not be explicitly qualified (e.g., `B<?>` which is not qualified but its type needs be calculated as seen from `A<String>.B<?>`).
> 
> Semi-formally: 
> 
> - A type reference is simple name `R`:
> 
>   - `R` is a non-inner class type, nothing to do
>   - `R` is an inner class type, we need to find an implicit type qualifier `S<T>.R`, where `S` is the class in which `R` is enclosed
>   - `R` is an array type `A[]`, repeat the analysis for the simple type name `A`, and then use the implicit type qualifier to rewrite the array
> 
> - A type reference is a qualified name `Q.R`
>   
>   - find the supertype of `Q`, namely `S<T>`, where `S` is the class in which `R` is enclosed
> 
> 
> 
> // example 1
> static class Usage1<T, G extends Getters<T>> {
>   public T test(G.Getter getter) {
>       return getter.get();
>   }
> }
> 
> // example 2
> class A<T> {
>   protected class B<V> {}
> 
>   public static <T, M extends A<T>> void f(Object g) {
>     @SuppressWarnings("unchecked")
>     M.B<?> mapping = (M.B<?>) g;
>   }
> }
> 
> // example 3
> class A<T> {
>     class B<W> {
>         public T rett() { return null; }
>     }
> }
> 
> class C extends A<String> {
>     static class D {
>         {
>             B<?> b = null;
>             String s = b.rett();
>         }
>     }
> }

Aggelos Biboudis has updated the pull request incrementally with one additional commit since the last revision:

  Apply suggestions from code review
  
  Co-authored-by: Chen Liang <liach at openjdk.org>

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/25451/files
  - new: https://git.openjdk.org/jdk/pull/25451/files/629ef2a7..4467d125

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25451&range=16
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25451&range=15-16

  Stats: 8 lines in 1 file changed: 0 ins; 2 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/25451.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25451/head:pull/25451

PR: https://git.openjdk.org/jdk/pull/25451