The DumpXXX() methods were always documented as internal and
unsupported. However, now they are being removed from the
public top-level API. They are still available on the internal
IndexReader, which can be accessed using the Advanced() method.
The DocCount() and DumpXXX() methods on the internal index
have moved to the internal index reader, since they logically
operate on a snapshot of an index.
the test had incorreclty been updated to compare the internal
document ids, but these are opaque and may not be the expected
ids in some cases, the test should simply check that it
corresponds to the correct external ids
