When lowering PathTraverse within EvalFilter, it is sometimes necessary to execute the LambdaAbstraction against each element of the array and the whole array itself, rather than just the elements of the array.

This approach is preferred to SERVER-62376 because we'd rather keep the ABT simple and allow the lowering code to inject the logic needed to handle these particular cases. See Fix ‘find({a: [1]})’ for ABT discussion for details.

Here are some examples where ABT->SBE lowering currently does not produce correct results:

• ‘find({a: [1]})’ should match both ‘{a: [1]}’ and ‘{a: [[1]]}’
• ‘find({a: {$in: [[1],[2]]}})’ should match both ‘{a: [1]}’ and ‘{a: [[1]]}’
• ‘find({a: {$type: “array”}})’ should match ‘{a: [1]}’ and ‘{a: [[1]]}’

This issue could potentially affect the $exists operator as well.

The goal of this task is to update ABT->SBE lowering so that it generates whatever is necessary to produce correct results for the cases listed above.