TestIndexWriterOutOfFileDescripters never reproduces [LUCENE-6273]

This test doesn't ever reproduce from the random seed.

Maybe we should write it differently? We could use HandleLimitFS:

```Java
* `@param` delegate delegate filesystem to wrap.
* `@param` limit maximum number of open files.
*/
public HandleLimitFS(FileSystem delegate, int limit) {
```

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Migrated from [LUCENE-6273](https://issues.apache.org/jira/browse/LUCENE-6273) by Robert Muir (@rmuir)

Locate the TestIndexWriterOutOfFileDescripters test and the HandleLimitFS class mentioned in the issue. Run the existing test with its current random-seed setup, then determine whether using HandleLimitFS makes the file-descriptor limit failure reproducible; done means the test reliably exercises the intended condition.

Written by the indexing model from the issue text.