Deprecated the @serializable annotation, introd...

Deprecated the @serializable annotation, introduce a new trait
"scala.Serializable" which has to be extended instead (cross-platform).

Known issues:
 - Companion objects of serializable classes (including case classes) are automatically made serializable. However, they don't extend "Serializable" statically because of the known difficulty (should be done before typing, but hard).
 - Writing "case class C() extends Serializable" gives "error: trait Serializable is inherited twice"
 - Functions are serializable, but don't extend Serializable dynamically (could be fixed by making FunctionN Serializable - shouldn't we?)

Note that @SerialVersionUID continues to be an annotation; it generates
a static field, which is not possible otherwise in scala.

Review by dragos, extempore.

Question to dragos: in JavaPlatform.isMaybeBoxed, why is there a test
for "JavaSerializableClass"? Is that correct?

1 files changed, 3 insertions, 2 deletions

diff --git a/src/library/scala/collection/mutable/LinkedHashMap.scala b/src/library/scala/collection/mutable/LinkedHashMap.scala
index f52aebed81..e08c7023cd 100644
--- a/src/library/scala/collection/mutable/LinkedHashMap.scala
+++ b/src/library/scala/collection/mutable/LinkedHashMap.scala
@@ -44,10 +44,11 @@ object LinkedHashMap extends MutableMapFactory[LinkedHashMap] {
  *  @define orderDependent
  *  @define orderDependentFold
  */
-@serializable @SerialVersionUID(1L)
+@SerialVersionUID(1L)
 class LinkedHashMap[A, B] extends Map[A, B]
                              with MapLike[A, B, LinkedHashMap[A, B]]
-                             with HashTable[A, LinkedEntry[A, B]] {
+                             with HashTable[A, LinkedEntry[A, B]]
+                             with Serializable {
 
   override def empty = LinkedHashMap.empty[A, B]
   override def size = tableSize