[cleanup] Split ForOf and ForIn AST nodes apart as they share little

src/compiler/ast-loop-assignment-analyzer.cc

Index: src/compiler/ast-loop-assignment-analyzer.cc
diff --git a/src/compiler/ast-loop-assignment-analyzer.cc b/src/compiler/ast-loop-assignment-analyzer.cc
index ac963997748b327d4c6d588b13aaea5e6175d7a2..334c5978a86f4088f80cb6af17d9b828980fae21 100644
--- a/src/compiler/ast-loop-assignment-analyzer.cc
+++ b/src/compiler/ast-loop-assignment-analyzer.cc
@@ -265,8 +265,9 @@ void ALAA::VisitForInStatement(ForInStatement* loop) {
 void ALAA::VisitForOfStatement(ForOfStatement* loop) {
   Visit(loop->assign_iterator());
   Enter(loop);
+  Visit(loop->next_result());
+  Visit(loop->result_done());
   Visit(loop->assign_each());
-  Visit(loop->subject());
   Visit(loop->body());
   Exit(loop);
 }