Expr.betaReduce can't reduce past the type ascription from inline def expansion

[fhackett]

minimized code

Macros_1.scala

import scala.quoted._

object Macros {
  inline def betaReduce[Arg,Result](inline fn: Arg=>Result)(inline arg: Arg): Result =
    ${ betaReduceImpl('{ fn })('{ arg }) }
  def betaReduceImpl[Arg,Result](fn: Expr[Arg=>Result])(arg: Expr[Arg]): Expr[Result] =
    Expr.betaReduce(fn)(arg)
}

Test_2.scala

import scala.compiletime._

object Test {
  inline def dummy: Int=>Int =
    (i: Int) => i + 1
  def main(argv: Array[String]): Unit = {
    println(code"${ Macros.betaReduce(dummy)(3) }")
  }
}

Output

(
  {
    def $anonfun(i: Int): Int = i.+(1)
    closure($anonfun)
  }
:Function1[Int, Int]).apply(
  {
    3
  }
)

expectation

4

[fhackett]

I had a go at fixing the issue. See #8251 for the proposed fix as well as some discussion.