Address reviews

Author: liufengyun

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -41,13 +41,14 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
     Super(qual, if (mixName.isEmpty) untpd.EmptyTypeIdent else untpd.Ident(mixName), inConstrCall, mixinClass)
 
   def Apply(fn: Tree, args: List[Tree])(implicit ctx: Context): Apply = {
-    assert(!fn.isInstanceOf[Block])
-    assert(!fn.isInstanceOf[If])
+    assert(fn.isInstanceOf[RefTree] || fn.isInstanceOf[GenericApply])
     ta.assignType(untpd.Apply(fn, args), fn, args)
   }
 
-  def TypeApply(fn: Tree, args: List[Tree])(implicit ctx: Context): TypeApply =
+  def TypeApply(fn: Tree, args: List[Tree])(implicit ctx: Context): TypeApply = {
+    assert(fn.isInstanceOf[RefTree] || fn.isInstanceOf[GenericApply])
     ta.assignType(untpd.TypeApply(fn, args), fn, args)
+  }
 
   def Literal(const: Constant)(implicit ctx: Context): Literal =
     ta.assignType(untpd.Literal(const))