Meta: Add Support unit tests

[paulirwin]

Is there an existing issue for this?

• I have searched the existing issues

Task description

This is a meta-issue that should be broken out into separate issues.

From #914 via @NightOwl888:

I also noticed we don't have tests for the following types in the Support folder:

• IndexableFieldExtensions (Add some Support unit tests, #920 #1093)
• ByteArrayOutputStream - Patch to provide ToString() output for MemoryStream. (Add some Support unit tests, #920 #1093)
• Add Support unit tests for StreamExtensions #1105
• ReferenceContext<T> - We added this to make it possible to use a using block instead of Acquire() with a try finally around Release(). We should convert this to a ref struct, so it doesn't cause a heap allocation to use. Ref structs cannot implement IDisposable, but the compiler allows a using block if Dispose() exists. Note that ReferenceManagerExtensions can be tested along with it.
  • Addressed in Lucene.Net.Search.ReferenceContext<T>: Converted to ref struct and reworked TestControlledRealTimeReopenThread.TestStraightForwardDemonstration() to verify functionality #925.
• Add Support unit tests for LimitedConcurrencyLevelTaskScheduler #1110
• Add Support unit tests for ReentrantLock #1111, BUG: Fix for DocumentsWriter concurrency (fixes #935, closes #886) #940
• CastTo<T> (Add some Support unit tests, #920 #1093)
• Add Support unit tests for ExceptionExtensions #1112
• ListExtensions (Add some Support unit tests, #920 #1093)
• SystemConsole - .NET should have some tests we can use for this. (This was removed instead in BREAKING: Remove SystemConsole class, #920, #936 #1113)
• Add Support unit tests for Arrays #1114
• AssemblyUtils (Add some Support unit tests, #920 #1093)
• Add Support unit tests for CollectionExtensions #1115
• Add Support unit tests for Collections #1116
• ConcurrentDictionaryWrapper<TKey, TValue> - This is no longer in use, we can probably eliminate it along with the DictionaryExtensions.AsConcurrent() extension method. It may come in handy for a future version of Lucene, though.
  • Fixed in Test review Core J-S, #259 #914
• Add Support unit tests for ConcurrentHashSet #1117
• Add Support unit tests for ConcurrentSet #1118
• DictionaryExtensions (Add some Support unit tests, #920 #1093)

[NightOwl888]

@paulirwin - Perhaps eliminating ConcurrentDictionaryWrapper<TKey, TValue> and friends should be a separate issue. Alternatively, it could be rolled into #259. If there is a need for a "ConcurrentLinkedDictionary" in later versions of Lucene, perhaps the implementation should be tagged or put on its own branch so we can recover it later.