Override LINQ Enumerable methods for ICollection/IList

[ndrwrbgs]

MDSN - Enumerable Methods

NOTE: When adding implementations, update #1 to add to the Benchmark TODO

Sequence modification methods

• Append
• AsEnumerable - Meant to stay in IEnumerable
• Cast
• Concat - needs some ICollection+IList permutations
• DefaultIfEmpty
• Distinct - Exact size cannot be known
• Except - Exact size cannot be known
• GroupBy - Exact size cannot be known
• GroupJoin
• Intersect - Exact size cannot be known
• Join
• OfType - Exact size cannot be known
• OrderBy
• OrderByDescending
• Prepend
• Reverse
• Select
• SelectMany - Exact size cannot be known
• Skip
• SkipWhile - Exact size cannot be known
• Take
• TakeWhile - Exact size cannot be known
• ThenBy
• ThenByDescending
• ToLookup - Exact size cannot be known
• Union - Exact size cannot be known
• Where - Exact size cannot be known
• Zip - needs some ICollection+IList permutations