Avoid constructing typed tree with untyped arguments

Author: smarter

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -720,7 +720,7 @@ trait Applications extends Compatibility { self: Typer with Dynamic =>
         }
 
       fun1.tpe match {
-        case err: ErrorType => untpd.cpy.Apply(tree)(fun1, tree.args).withType(err)
+        case err: ErrorType => untpd.cpy.Apply(tree)(fun1, proto.typedArgs).withType(err)
         case TryDynamicCallType => typedDynamicApply(tree, pt)
         case _ =>
           if (originalProto.isDropped) fun1

tests/neg/parser-stability-6.scala

@@ -0,0 +1,3 @@
+class x0 {
+  1 + x1 * / |= 2 // error: not found: x1
+}