WIP: type profiling.

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index 7983feb0f5a32d1a7e1bd0a49d23a8a4ec39d7f4..d48c5afce067ba241eb87650412550e08fdab5f4 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -2440,6 +2440,10 @@ class Assignment final : public Expression {
                            FeedbackSlotCache* cache);
   FeedbackSlot AssignmentSlot() const { return slot_; }
 
+  FeedbackSlot CollectTypeProfileSlot() const {
+    return collect_type_profile_slot_;
+  }
+
  private:
   friend class AstNodeFactory;
 
@@ -2457,6 +2461,7 @@ class Assignment final : public Expression {
   class TokenField : public BitField<Token::Value, StoreModeField::kNext, 7> {};
 
   FeedbackSlot slot_;
+  FeedbackSlot collect_type_profile_slot_;
   Expression* target_;
   Expression* value_;
   BinaryOperation* binary_operation_;