Inlined inline val reference does not get constant folded

[nicolasstucki]

Minimized code

class C:
  type X <: Tuple

inline def f(c: C): Unit = {
  inline val size = compiletime.constValue[Tuple.Size[c.X]]
  val n = size
  val m: Int = n
  ???
}

def test: Unit = f(??? : C { type X = Tuple1[Any] })

Output

result after typer:
...
def test: Unit = 
      {
        val c: C{X = Tuple1[Any]} = 
          ??? :
            C 
              {
                type X = Tuple1[Any]
              }
        {
          inline val size: (1 : Int) = 1
          val n: (1 : Int) = size
          val m: Int = n
          ???
        }:Unit
      }
...
result after genBCode:
...
    def test(): Unit = 
      {
        val c: C = ???():C
        {
          {
            inline val size: Int = 1
            val n: Int = size
            val m: Int = n
            ???()
          }:scala.runtime.BoxedUnit
          ()
        }
      }
...

Expectation

The reference to size should be replaced by the literal constant 1. This is needed to ensure that all local inline vals can be erased.

[nicolasstucki]

Related to #8836