Type leaking out of block because of synthesizedClassTag

[OlivierBlanvillain]

import reflect.ClassTag

object Demo {
  def the[T](implicit ev: T): ev.type = ev // More precise implicitly, needed to crash

  {
    case class B(i: Int)
    the[ClassTag[B]] // Has to be the last statement of the block
  }
}

Crashes with the following:

Exception in thread "main" java.lang.AssertionError: assertion failed: leak: B in {
  case class B(i: Int) extends Object() with _root_.scala.Product {
    val i: Int
    def copy(i: Int): B = new B(i)
    def copy$default$1: Int @uncheckedVariance =
      B.this.i: Int @uncheckedVariance
    def _1: Int = this.i
  }
  final lazy module val B: B = new B()
  final module class B() extends Object() with Function1[Int, B] {
    this: B.type =>

    def apply(i: Int): B = new B(i)
    def unapply(x$1: B): B = x$1
  }
  Demo.the[reflect.ClassTag[B]](
    scala.reflect.ClassTag.apply[B](classOf[class B])
  ): ClassTag[B](?1)
}
        at scala.Predef$.assert(Predef.scala:219)
        at dotty.tools.dotc.typer.Typer.ensureNoLocalRefs(Typer.scala:671)
        at dotty.tools.dotc.typer.Typer.$anonfun$typedBlock$1(Typer.scala:634)
        ...