Rewrite ClassTag and ScalaRunTime for new representation of arrays of value classes

Author: VladimirNik

src/scala/reflect/ClassTag.scala

@@ -150,6 +150,8 @@ object ClassTag {
       case ObjectTYPE               => ClassTag.Object.asInstanceOf[ClassTag[T]]
       case NothingTYPE              => ClassTag.Nothing.asInstanceOf[ClassTag[T]]
       case NullTYPE                 => ClassTag.Null.asInstanceOf[ClassTag[T]]
+      case _ if classOf[dotty.runtime.vc.VCPrototype].isAssignableFrom(runtimeClass1) =>
+        Class.forName(s"${runtimeClass1.getName()}$$").newInstance().asInstanceOf[ClassTag[T]]
       case _                        => new ClassTag[T]{ def runtimeClass = runtimeClass1 }
     }
 

src/scala/runtime/ScalaRunTime.scala

@@ -58,7 +58,11 @@ object ScalaRunTime {
     //  at scala.Array$.fill(Array.scala:281)
     //  at dotty.tools.dotc.core.Flags$.<init>(Flags.scala:139)
     // newInstance throws an exception if the erasure is Void.TYPE. see SI-5680
+    // TODO: update comment
+    // Vladimir: this method is used in the process of ClassTag generation in several methods of scala.Array
+    // ClassTag..MODULE$.apply(ScalaRunTime..MODULE$.arrayClass(ScalaRunTime..MODULE$.arrayClass(evidence$5.runtimeClass()))));
     if (clazz == java.lang.Void.TYPE) classOf[Array[Unit]]
+    else if (classOf[dotty.runtime.vc.VCPrototype].isAssignableFrom(clazz)) ClassTag(clazz).wrap.runtimeClass
     else java.lang.reflect.Array.newInstance(clazz, 0).getClass
   }