[Interpreter] Optimize code of the form 'if (x === undefined)'.

src/interpreter/bytecode-generator.h

Index: src/interpreter/bytecode-generator.h
diff --git a/src/interpreter/bytecode-generator.h b/src/interpreter/bytecode-generator.h
index 698d0c24032b13f5f52d006f9b5bd816431f2cee..846731b16d2364eb7dd5864ae9648cb039dacda3 100644
--- a/src/interpreter/bytecode-generator.h
+++ b/src/interpreter/bytecode-generator.h
@@ -109,7 +109,7 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   void BuildVariableAssignment(Variable* variable, Token::Value op,
                                FeedbackSlot slot,
                                HoleCheckMode hole_check_mode);
-
+  void BuildLiteralCompareNil(Token::Value compare_op, NilValue nil);
   void BuildReturn();
   void BuildAsyncReturn();
   void BuildAsyncGeneratorReturn();