A.java

import java.util.ArrayList;

class A {

    interface Function<B, C> {
        C apply(B input);
    }

    private <B,C> Iterable<C> transform(Iterable<B> iterable, Function<? super B, ? extends C> transform) {
        // impl not relevant for bug
        return new ArrayList<>();
    }

    public static class In<V> {}
    public static class Out<V> {}

    public <V> Out<V> fn(In<V> in) {
        return null;
    }

    public void myMethod() {
        Iterable<In<?>> ins = new ArrayList<>();

        Iterable<Out<?>> outs = transform(ins, this::fn);
    }
}

Using Sun Java 1.8.0_45:
javac A.java => success

Using ECJ 4.6M5:
java -jar ecj-4.6M5.jar -source 1.8 -target 1.8 A.java => failure

Output:

----------
1. ERROR in /home/cmyers/projects/private_notes/persistent/bugs/20160205-jdk-versus-ecj/A.java (at line 24)
        Iterable<Out<?>> outs = transform(ins, this::fn);
                               ^^^^^^^^^^^^^^^^^^^^^^^^
Type mismatch: cannot convert from Iterable<Object> to Iterable<A.Out<?>>
----------
1 problem (1 error)