Add support for parametrized types

[jbgi]

Currently polymorphic target are not supported. I think the following:

@Goal(name = "entry")
  static <K, V> Map.Entry<K, V> entry(K key, V value) {
    return new AbstractMap.SimpleEntry<K, V>(key, value);
  }

should generate something like:

  [...]
  public static EntryBuilder.Key entryBuilder() {
    return INSTANCE.get().entryBuilderImpl;
  }
  private static final class EntryBuilderImpl implements EntryBuilder.Key,
                                                         EntryBuilder.Value<Object> {
    private Object key;
    EntryBuilderImpl() { }
    @Override
    public <K> EntryBuilder.Value<K> key(K key) {
      this.key = key;
      return (EntryBuilder.Value<K>) this;
    }
    @Override
    public <V> Map.Entry<Object, V> value(V value) {
      Object key = this.key;
      this.key = null;
      return Request.entry(key, value);
    }
  }
  public static final class EntryBuilder {
    private EntryBuilder() {
      throw new UnsupportedOperationException("no instances");
    }
    public interface Key {
      <K> Value<K> key(K key);
    }
    public interface Value<K> {
      <V> Map.Entry<K, V> value(V value);
    }
  }

if recycling is activated.

[h908714124]

Thanks @jbgi this looks natural. After modularisation of the API is complete, this will go in the builder module. It seems like the other module, updater, will not be affected.

[h908714124]

First attempt: https://github.com/h908714124/zerobuilder/blob/9b235bdbd36ddfe8513c2075ebe962b2934b70b5/examples/basic/src/test/java/net/zerobuilder/examples/generics/MapEntryTest.java

recycle, @Step and non-static goal methods don't work yet.

[h908714124]

Release 1.522 supports type variables. In goals with typevars, recycle is currently ignored, and update is forbidden.

[h908714124]

1.523 finally also generates a generic updater, see GenericConstructor.java.