Fix some cc errors

Author: noti0na1

library/src/scala/collection/Iterator.scala

@@ -189,7 +189,7 @@ trait Iterator[+A] extends IterableOnce[A] with IterableOnceOps[A, Iterator, Ite
      *  @note    This method is mutually exclusive with `withPartial`.
      *  @group Configuration
      */
-    def withPadding(x: => B): this.type = {
+    def withPadding(x: -> B): this.type = {
       padding = () => x
       partial = true        // redundant, as padding always results in complete segment
       this

library/src/scala/collection/SeqView.scala

@@ -138,7 +138,7 @@ object SeqView {
     extends SeqView[A] {
     outer: Sorted[A, B]^ =>
 
-    private var underlying: SomeSeqOps[A] | Null = underlying_
+    private var underlying: SomeSeqOps[A]^{underlying_} | Null = underlying_
 
     // force evaluation immediately by calling `length` so infinite collections
     // hang on `sorted`/`sortWith`/`sortBy` rather than on arbitrary method calls

library/src/scala/collection/mutable/ListBuffer.scala

@@ -125,7 +125,7 @@ class ListBuffer[A]
   }
 
   // MUST only be called on fresh instances
-  private def freshFrom(xs: IterableOnce[A]): this.type = {
+  private def freshFrom(xs: IterableOnce[A]^): this.type = {
     val it = xs.iterator
     if (it.hasNext) {
       var len = 1
@@ -144,7 +144,7 @@ class ListBuffer[A]
     this
   }
 
-  override final def addAll(xs: IterableOnce[A]): this.type = {
+  override final def addAll(xs: IterableOnce[A]^): this.type = {
     val it = xs.iterator
     if (it.hasNext) {
       val fresh = new ListBuffer[A].freshFrom(it)
@@ -253,7 +253,7 @@ class ListBuffer[A]
     }
   }
 
-  def insertAll(idx: Int, elems: IterableOnce[A]): Unit = {
+  def insertAll(idx: Int, elems: IterableOnce[A]^): Unit = {
     if (idx < 0 || idx > len) throw CommonErrors.indexOutOfBounds(index = idx, max = len - 1)
     val it = elems.iterator
     if (it.hasNext) {

library/src/scala/collection/mutable/UnrolledBuffer.scala

@@ -380,7 +380,7 @@ object UnrolledBuffer extends StrictOptimizedClassTagSeqFactory[UnrolledBuffer]
       if (next eq null) true else false // checks if last node was thrown out
     } else false
 
-    @tailrec final def insertAll(idx: Int, t: scala.collection.IterableOnce[T], buffer: UnrolledBuffer[T]): Int = {
+    @tailrec final def insertAll(idx: Int, t: scala.collection.IterableOnce[T]^, buffer: UnrolledBuffer[T]): Int = {
       if (idx < size) {
         // divide this node at the appropriate position and insert all into head
         // update new next