Update TreeChecker to ignore erased functions

Just like poly functions, erased functions stay structural until erasure.

Author: natsukagami

compiler/src/dotty/tools/dotc/transform/TreeChecker.scala

@@ -392,10 +392,12 @@ class TreeChecker extends Phase with SymTransformer {
 
       // Polymorphic apply methods stay structural until Erasure
       val isPolyFunctionApply = (tree.name eq nme.apply) && tree.qualifier.typeOpt.derivesFrom(defn.PolyFunctionClass)
+      // Erased functions stay structural until Erasure
+      val isErasedFunctionApply = (tree.name eq nme.apply) && tree.qualifier.typeOpt.derivesFrom(defn.ErasedFunctionClass)
       // Outer selects are pickled specially so don't require a symbol
       val isOuterSelect = tree.name.is(OuterSelectName)
       val isPrimitiveArrayOp = ctx.erasedTypes && nme.isPrimitiveName(tree.name)
-      if !(tree.isType || isPolyFunctionApply || isOuterSelect || isPrimitiveArrayOp) then
+      if !(tree.isType || isPolyFunctionApply || isErasedFunctionApply || isOuterSelect || isPrimitiveArrayOp) then
         val denot = tree.denot
         assert(denot.exists, i"Selection $tree with type $tpe does not have a denotation")
         assert(denot.symbol.exists, i"Denotation $denot of selection $tree with type $tpe does not have a symbol, qualifier type = ${tree.qualifier.typeOpt}")