Merge pull request #8815 from dotty-staging/fix-#8729

Fix #8729: Drop failing assertion in `enter`

Author: bishabosha

compiler/src/dotty/tools/dotc/core/SymDenotations.scala

@@ -1810,13 +1810,7 @@ object SymDenotations {
  */
  def enter(sym: Symbol, scope: Scope = EmptyScope)(implicit ctx: Context): Unit = {
  val mscope = scope match {
- case scope: MutableScope =>
- // if enter gets a scope as an argument,
- // than this is a scope that will eventually become decls of this symbol.
- // And this should only happen if this is first time the scope of symbol
- // is computed, ie symbol yet has no future.
- assert(this.nextInRun.validFor.code <= this.validFor.code)
- scope
+ case scope: MutableScope => scope
  case _ => unforcedDecls.openForMutations
  }
  if (proceedWithEnter(sym, mscope)) {