Allow Object members on unknown types

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt

@@ -2027,10 +2027,14 @@ class BytecodeCompiler(
 
     private fun compileFieldRef(ref: FieldRef): CompiledValue? {
         val receiverClass = resolveReceiverClass(ref.target)
-            ?: throw BytecodeCompileException(
-                "Member access requires compile-time receiver type: ${ref.name}",
-                Pos.builtIn
-            )
+            ?: if (isAllowedObjectMember(ref.name)) {
+                Obj.rootObjectType
+            } else {
+                throw BytecodeCompileException(
+                    "Member access requires compile-time receiver type: ${ref.name}",
+                    Pos.builtIn
+                )
+            }
         val fieldId = receiverClass.instanceFieldIdMap()[ref.name]
         val methodId = receiverClass.instanceMethodIdMap(includeAbstract = true)[ref.name]
         val receiver = compileRefWithFallback(ref.target, null, Pos.builtIn) ?: return null

lynglib/stdlib/lyng/root.lyng

@@ -291,7 +291,7 @@ override fun List<T>.toString() {
     var result = "["
     for (item in this) {
         if (!first) result += ","
-        result += (item as Object).toString()
+        result += item.toString()
         first = false
     }
     result + "]"
@@ -311,7 +311,7 @@ fun List<T>.sort(): Void {
 fun Exception.printStackTrace(): Void {
     println(this)
     for( entry in stackTrace ) {
-        println("\tat "+(entry as Object).toString())
+        println("\tat "+entry.toString())
     }
 }