Remove InfixOpBlock

And add a comment on possibly ode types returned from typedApply

Author: odersky

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -96,16 +96,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
     override def isEmpty = true
   }
 
-  /** A block arising from a right-associative infix operation, where, e.g.
-   *
-   *     a +: b
-   *
-   *  is expanded to
-   *
-   *     { val x = a; b.+:(x) }
-   */
-  class InfixOpBlock(leftOperand: Tree, rightOp: Tree) extends Block(leftOperand :: Nil, rightOp)
-
   /** A block generated by the XML parser, only treated specially by
    *  `Positioned#checkPos` */
   class XMLBlock(stats: List[Tree], expr: Tree) extends Block(stats, expr)