Implicit search fails for new Random.shuffle(List(1,2))

[smarter]

This compiles with scalac but not with dotty:

import scala.util.Random

object Test {
  def test = {
    val rand = new Random
    rand.shuffle(List(1,2)) // fails
  }
}

try/t6948b.scala:6: error: no implicit argument of type scala.collection.generic.CanBuildFrom[
  (CC?
     >: ([+HK$0] => scala.collection.immutable.List[HK$0])[HK$0 =+ (T? >: Int)]
       <: 
    ([HK$0] =>  <: scala.collection.TraversableOnce[HK$0])
  )[(T? >: Int)]#Apply
, (T? >: Int), 
  (CC?
     >: ([+HK$0] => scala.collection.immutable.List[HK$0])[HK$0 =+ (T? >: Int)]
       <: 
    ([HK$0] =>  <: scala.collection.TraversableOnce[HK$0])
  )[(T? >: Int)]#Apply
] found for parameter bf of method shuffle in class Random
    rand.shuffle(List(1,2))
                           ^
one error found

But explicitly doing an implicit search is enough to make it work:

import scala.util.Random
import scala.collection.generic._
import scala.collection.immutable._

object Test {
  implicit val z: CanBuildFrom[List[Int], Int, List[Int]] =
    implicitly[CanBuildFrom[List[Int], Int, List[Int]]] // succeeds

  def test = {
    val rand = new Random
    rand.shuffle(List(1,2)) // now succeeds
  }
}

[smarter]

Fixed by #799.