Bug ID: JDK-8029704 Lambda Spec: Fix subtype inference for a non-parameterized inner class of a generic type

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JDK 8
8Fixed

Uses of a class like Inner, below, are not parameterized types (per JLS 4.5).

class Outer<T> {
  abstract class Inner { abstract T get(); }

  static <X> X unwrap(Outer<X>.Inner i) { return i.get(); }

  static void test(Outer<String>.Inner i) {
    unwrap(i).substring(3);
  }

}

But, clearly, subtype inference should treat it just like a parameterized type.  The rules in 18.2.3 should be modified to allow, e.g., x=String to be inferred above.

Updated text for 18.2.4: Otherwise, if S and T *are class or interface types with the same erasure, where S has type arguments B1, ..., Bn and T has type arguments A1, ..., An,* the constraint reduces to the following new constraints: for all i, 1 �� i �� n, ��Bi = Ai��.
18-12-2013
Updated text for 18.2.3: Otherwise, the constraint is reduced according to the form of T: - If T is a parameterized class *or interface type, or an inner class type of a parameterized class or interface type (directly or indirectly), let A1, ..., An be the type arguments appearing in T; among the supertypes (4.10) of S, a corresponding class or interface type is identified, with type arguments B1, ..., Bn. If no such type exists,* the constraint reduces to false. Otherwise, the constraint reduces to the following new constraints: for all i, 1 �� i �� n, ��Bi <= Ai��. - If T is *any other class or interface type, then the constraint reduces to true if T is among the supertypes of S*, and false otherwise. [This is somewhat awkward, because there doesn't seem to be a related treatment of inner class types in 4.10. See JDK-8030746.]
18-12-2013
Also need to consider the parallel in 18.2.4, Type Equality Constraints.
11-12-2013
Also need to consider inner classes as they relate to the clause "If T is a non-parameterized class or interface type" (does not consider the possibility that T may be an inner class of a parameterized type).
11-12-2013
Reported by Stephan Herrmann on lambda-spec-experts@openjdk.java.net.
06-12-2013

Relates :	JDK-8029885 - javac, fix subtype inference for a non-parameterized inner class of a generic type
Relates :	JDK-8030746 - 4.10: Define subtyping for inner classes of parameterized types