Add Value classes and array prototypes.

Making actual value classes extend this prototypes serves two goals:
 - This is a basis for implementing arrays of value classes.
 - Having underlying final in those glasses makes all unbox methods monomorphic and final.
 - this decreases size of an empty case-class to 1/3 of previous size.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/dotty/runtime/vc/VCPrototype.scala b/src/dotty/runtime/vc/VCPrototype.scala
new file mode 100644
index 000000000..5b43e74f4
--- /dev/null
+++ b/src/dotty/runtime/vc/VCPrototype.scala
@@ -0,0 +1,14 @@
+package dotty.runtime.vc
+
+abstract class VCPrototype {
+}
+
+abstract class VCCompanionPrototype {
+
+}
+
+abstract class VCArrayPrototype[T <: VCPrototype] {
+  def apply(idx: Int): Object
+  def update(idx: Int, el: T): Unit
+  def length: Int
+}