[2.13.0-M4] missing classes on scala.collection.mutable

[MasseGuillaume]

• ArrayStack
• FlatHashTable
• HashTable (now private, implementation details)
• History
• LazyBuilder
• LinearSeq
• LinkedEntry (removed, Class for the linked hash map entry, used internally.)
• MapBuilder
• MutableList
• Publisher
• ResizableArray
• RevertibleHistory
• SetBuilder
• StackBuilder
• Subscriber
• Undoable
• WrappedArray
• WrappedArrayBuilder

[julienrf]

I think we should just document that in the FAQ (for now).

[julienrf]

I’ve added this list of unsupported types to the FAQ: https://github.com/scala/collection-strawman/wiki/FAQ#what-are-the-breaking-changes

I suggest closing this issue for now. We can see later if we should invest in a better compatibility layer for these removed classes.

[erikerlandson]

I am running into lack of MapBuilder on typelevel/spire#759

[SethTisue]

I am running into lack of MapBuilder on non/spire#759

Map.newBuilder should cross-compile. (but perhaps you're in some special situation?)