Select symbols also need to be modified in TreeTypeMap\TreeMap

[DarkDimius]

Such code will break extensionMethods(and similar breaks tailcalls).

package dotty.tools.dotc
package transform

import dotty.tools.dotc.core.Denotations._
import dotty.tools.dotc.core.Symbols._
import dotty.tools.dotc.core.Contexts._

class TC5(val ctx: Context) extends AnyVal {
  def candidates(mbr: SingleDenotation): Boolean = {
    implicit val c: Context = ctx
    mbr.symbol.exists
  }
}

After creating a fullyParameterizedDef, Select(mbr, 'symbol') has invalid symbol and thus NoType. Ycheck will die trying to find implicit conversion.

[retronym]

While the tree/type maps should probably handle this, value classes should not be allowed to have val members.

[DarkDimius]

@retronym thanks, I've restructured test so that it is correct from that perspective and can be compiled by scalac