Support valueOf of singleton tuples

[Swoorup]

Currently this gives:

scala> valueOf[("test", "bla")];;
1 |valueOf[("test", "bla")];;
  |^^^^^^^^^^^^^^^^^^^^^^^^
  |cannot reduce summonFrom with
  | patterns :  case ev @ _:ValueOf[(("test" : String), ("bla" : String))]
  | This location contains code that was inlined from Predef.scala:25

As @Odomontois pointed out in gitter something like this could support tuple singletons:

import scala.compiletime._

inline def tupleValues[A <: Tuple]: A = 
    inline erasedValue[A] match
        case _ : (t *: ts) => 
            summonInline[t *: ts <:< A](valueOf[t] *: tupleValues[ts])
        case _ : EmptyTuple => 
            summonInline[EmptyTuple <:< A](EmptyTuple)

[bishabosha]

For now, you can make a similar abstraction using compiletime.constValueTuple:

final class ReflectType[T](val asValue: T) extends AnyVal {
  type Refl = T
  def refl: Refl = asValue
}

def reflectType[T](using refl: ReflectType[T]): refl.Refl = refl.refl

// forces bounds to be fixed in pattern match
final abstract class TypeBox[T]()

transparent inline given genReflectType[T]: ReflectType[T] = inline compiletime.erasedValue[TypeBox[T]] match {
  case _: TypeBox[t *: ts]    => ReflectType(compiletime.constValueTuple[t *: ts])
  case _: TypeBox[EmptyTuple] => ReflectType(EmptyTuple)
  case _: TypeBox[T]          => ReflectType(valueOf[T])
}

val one: 1 = reflectType[1]
val many: (1,"msg",true) = reflectType[(1,"msg",true)]

[Swoorup]

Thank you.
Now, I wonder whether this should apply to case classes or any other type as well, where all members are of singleton types.