Array creation is intrinsically non-null

[wmdietl]

I noticed when working on jspecify/jspecify#678 that the Nullness Checker currently accepts @Nullable on the created array:

import org.checkerframework.checker.nullness.qual.Nullable;

public class ADemo {
  void foo() {
    int [] o = new int @Nullable [10];
    o.hashCode();
  }
}

An error is raised on the o.hashCode() even though that reference is intrinsically non-null.

Like for object creation, an array creation cannot be @Nullable. (Check other possible qualifiers, also initialization).

[thisisalexandercook]

@wmdietl I'm unable to reproduce the error raised on o.hashCode but will work on updating checker to not accept qualifier on array creation.

[wmdietl]

Ah, I had used a 2 year old CF version... that produced:

> ./checker/bin/javac -processor nullness ADemo.java
ADemo.java:6: error: [dereference.of.nullable] dereference of possibly-null reference o
    o.hashCode();
    ^
1 error

It doesn't really make sense, because the logic that makes array creations non-null has been there for a long while.

Let's just produce a warning that the @Nullable in the example is ignored.