RETURNS_DEEP_STUBS override a mock's toString to null

[strulovich]

This example describes the issue:

  @Test
  public void mocksWithDeepStubsReturnNameOnToString() {
    Object proudMock = Mockito.mock(
        Object.class,
        Mockito.withSettings()
            .name("I'm a mock!")
            .defaultAnswer(Mockito.RETURNS_DEEP_STUBS));

    // fails, toString() returns null
    assertThat(proudMock.toString()).isEqualTo("I'm a mock!");
  }

I'm experiencing this on 2.26.0, (looking at ReturnsDeepStubs looks like it hasn't changed much since then).

I think toString should still return the mock's name, right now it returns a null.