Structural Equality: Treat ImmutableArray<T> the same as Array

[NightOwl888]

Since ImmutableArray<T> is yet another array implementation of IStructuralEquatable that could be compared against Array, it must be treated like an Array, not compared using IStructuralEquatable.

There are several places in the codebase where we do this:

• CollectionUtil
  • https://github.com/NightOwl888/J2N/blob/b7f80ca424af2b077b5d42beff4d9fbad8b05ef5/src/J2N/Collections/ArrayEqualityUtil.cs#L114
  • https://github.com/NightOwl888/J2N/blob/b7f80ca424af2b077b5d42beff4d9fbad8b05ef5/src/J2N/Collections/ArrayEqualityUtil.cs#L259
• StructuralEqualityComparer

  • J2N/src/J2N/Collections/StructuralEqualityComparer.cs

    Line 83 in b7f80ca

    if (x is Array arrayX && y is Array arrayY) // J2N TODO: Add support for multiple dimensional arrays

  • J2N/src/J2N/Collections/StructuralEqualityComparer.cs

    Line 133 in b7f80ca

    if (o1 is Array array1 && o2 is Array array2) // J2N TODO: Add support for multiple dimensional arrays

  • J2N/src/J2N/Collections/StructuralEqualityComparer.cs

    Line 177 in b7f80ca

    if (obj is Array array && array.Rank == 1) // J2N TODO: Add support for multiple dimensional arrays

  • J2N/src/J2N/Collections/StructuralEqualityComparer.cs

    Line 208 in b7f80ca

    if (element is Array nestedArray && nestedArray.Rank == 1)

Unfortunately, we have some challenges to deal with, since if we don't know the generic closing type of ImmutableArray<T>, we will need to do some work to materialize it before we can compare it.