Remove dead code testing for Array[Unit] after Array[AnyRef].

Since `Array[Unit]` is implemented as `Array[BoxedUnit]`, any
`Array[Unit]` already qualifies as an `Array[AnyRef]`. Therefore,
all the removed cases were dead code.

Author: sjrd

library/src/scala/runtime/ScalaRunTime.scala

@@ -64,7 +64,6 @@ object ScalaRunTime {
       case x: Array[Byte]    => x(idx).asInstanceOf[Any]
       case x: Array[Short]   => x(idx).asInstanceOf[Any]
       case x: Array[Boolean] => x(idx).asInstanceOf[Any]
-      case x: Array[Unit]    => x(idx).asInstanceOf[Any]
       case null => throw new NullPointerException
     }
   }
@@ -81,7 +80,6 @@ object ScalaRunTime {
       case x: Array[Byte]    => x(idx) = value.asInstanceOf[Byte]
       case x: Array[Short]   => x(idx) = value.asInstanceOf[Short]
       case x: Array[Boolean] => x(idx) = value.asInstanceOf[Boolean]
-      case x: Array[Unit]    => x(idx) = value.asInstanceOf[Unit]
       case null => throw new NullPointerException
     }
   }
@@ -97,7 +95,6 @@ object ScalaRunTime {
     case x: Array[Byte]    => x.length
     case x: Array[Short]   => x.length
     case x: Array[Boolean] => x.length
-    case x: Array[Unit]    => x.length
     case null => throw new NullPointerException
   }
 
@@ -111,7 +108,6 @@ object ScalaRunTime {
     case x: Array[Byte]    => x.clone()
     case x: Array[Short]   => x.clone()
     case x: Array[Boolean] => x.clone()
-    case x: Array[Unit]    => x
     case null => throw new NullPointerException
   }
 
@@ -143,7 +139,6 @@ object ScalaRunTime {
       case x: Array[Byte]    => copy(x)
       case x: Array[Short]   => copy(x)
       case x: Array[Boolean] => copy(x)
-      case x: Array[Unit]    => copy(x)
       case null => throw new NullPointerException
     }
   }