[I] [Scala] Native mode rebuilds IntMap, LongMap, BitSet, mutable.LongMap and StringBuilder as a different collection class [fory]

["pjfanning (via GitHub)" <gi...@apache.org>]

pjfanning opened a new issue, #4102:
URL: https://github.com/apache/fory/issues/4102

   ### Search before asking
   
   - [x] I had searched in the issues and found no similar issues.
   
   ### Version
   
   `main` (1.8.0-SNAPSHOT), Scala 2.13.18 and 3.3.8
   
   ### Component(s)
   
   Scala
   
   ### Minimal reproduce step
   
   ```scala
   import org.apache.fory.scala.ForyScala
   import scala.collection.immutable
   
   case class Holder(m: immutable.IntMap[String])
   
   val fory = ForyScala.builder()
     .withXlang(false)
     .withRefTracking(true)
     .requireClassRegistration(false)
     .build()
   
   fory.deserialize(fory.serialize(Holder(immutable.IntMap(1 -> "a"))))
   // DeserializationException caused by
   // ClassCastException: scala.collection.immutable.Map$Map1 cannot be cast to scala.collection.immutable.IntMap
   ```
   
   ### What did you expect to see?
   
   A native-mode round trip should rebuild the same collection class, as it already does for `List`, `Vector`, `HashMap`, `TreeMap`, `LinkedHashMap` and others.
   
   ### What did you see instead?
   
   The native Scala collection serializers write the value's generic factory, `iterableFactory`, `mapFactory` or `sortedIterableFactory`. For these specialised kinds that factory builds a different class. The same happens in compatible and schema-consistent modes:
   
   | Written | Read back as | As a declared case class field |
   | --- | --- | --- |
   | `immutable.IntMap` | `immutable.Map$Map1` / `Map` | `ClassCastException` |
   | `immutable.LongMap` | `immutable.Map$Map1` / `Map` | `ClassCastException` |
   | `mutable.BitSet` | `mutable.TreeSet` | `ClassCastException` |
   | `mutable.LongMap` | `mutable.HashMap` | `ClassCastException` |
   | `mutable.StringBuilder` | `mutable.ArrayBuffer[Char]` | `ClassCastException` |
   | `immutable.ArraySeq[Int]` (`ArraySeq$ofInt`) | `ArraySeq$ofRef` (boxed) | works, but loses the unboxed representation |
   
   As a root value, the decoded collection compares equal to the original, so the change goes unnoticed until a typed field or a pattern match depends on the concrete class.
   
   ### Anything Else?
   
   The factories are chosen in `ScalaCollectionSerializer`, `ScalaSeqSerializer`, `ScalaSortedSetSerializer` and `ScalaMapSerializer` (`CollectionSerializer.scala` and `MapSerializer.scala`). These kinds probably need their specific factory or a dedicated serializer, for example `IntMap`/`LongMap` factories, `BitSet` from its bitmask, `StringBuilder` as a string, and `ArraySeq` keeping its element `ClassTag`.
   
   Related: #4101 covers the registration gap for several of the same types. Found while adding tests in #4100.
   
   ### Are you willing to submit a PR?
   
   - [x] I'm willing to submit a PR!
   


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