ReplCompiler should include unrolling phase

[bishabosha]

Compiler version

3.7.1

Minimized example

with scala repl -S 3.7.1 -experimental -Xprint:pickler

import scala.annotation.unroll

case class Foo(x: Int, @unroll y: Option[String] = None)

Output

final module class Foo() extends AnyRef(), scala.deriving.Mirror.Product {
      this: Foo.type =>
      private def writeReplace(): AnyRef =
        new scala.runtime.ModuleSerializationProxy(classOf[Foo.type])
      def apply(x: Int, y: Option[String]): Foo = new Foo(x, y)
      def unapply(x$1: Foo): Foo = x$1
      override def toString: String = "Foo"
      def $lessinit$greater$default$2: Option[String] @uncheckedVariance = None
      type MirroredMonoType = Foo
      def fromProduct(x$0: Product): Foo.MirroredMonoType =
        {
          val arity: Int = x$0.productArity
          val x$1: Int = x$0.productElement(0).$asInstanceOf[Int]
          val y$1: Option[String] =
            (if arity > 1 then x$0.productElement(1) else 
              Foo.$lessinit$greater$default$2).$asInstanceOf[Option[String]]
          new Foo(x$1, y$1)
        }
    }

Expectation

this was very confusing that only fromProduct seemed to be unrolled correctly, until i remembered that fromProduce is unrolled in the PostTyper phase, and so it appears that the main unroll phase wasn't even ran. And upon checking, indeed the ReplCompiler frontend stops after PostTyper and does not include UnrollDefinitions