Join's TermsIncludingScoreQuery Weight has wrong normalization [LUCENE-4939]

In the Join module, TermsIncludingScoreQuery's Weight implementation looks suspiciously wrong. It creates a Weight based on the original query and delegates a couple calls to it in getValueForNormalization() and normalize() – ok fine. But then it doesn't do anything with it! Furthermore, the original query has already been run by this point anyway.

Question: Should the original query, which currently runs separately (see JoinUtil), participate in the Weight normalization of the main query? It would be tricky to wire all this together based on the current structure but arguably that is more correct.

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Migrated from [LUCENE-4939](https://issues.apache.org/jira/browse/LUCENE-4939) by David Smiley (@dsmiley)

Start in the Join module with TermsIncludingScoreQuery's Weight implementation, then trace the original query's separate execution in JoinUtil. Determine whether that query should participate in normalization of the main query and how the current structure could support it. Done means the normalization behavior is resolved and covered by relevant tests.

Written by the indexing model from the issue text.