Check for let in lexically bound names for short object literals

src/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/bailout-reason.h"
 #include "src/expression-classifier.h"
 #include "src/func-name-inferrer.h"
@@ skipping 2630 matching lines @@
       // PropertyDefinition
       //    IdentifierReference
       //    CoverInitializedName
       //
       // CoverInitializedName
       //    IdentifierReference Initializer?
       if (classifier->duplicate_finder() != nullptr &&
           scanner()->FindSymbol(classifier->duplicate_finder(), 1) != 0) {
         classifier->RecordDuplicateFormalParameterError(scanner()->location());
       }
+      if (name_token == Token::LET) {
+        classifier->RecordLetPatternError(
+            scanner()->location(), MessageTemplate::kLetInLexicalBinding);
+      }
 
       ExpressionT lhs = this->ExpressionFromIdentifier(
           name, next_beg_pos, next_end_pos, scope_, factory());
 
       if (peek() == Token::ASSIGN) {
         this->ExpressionUnexpectedToken(classifier);
         Consume(Token::ASSIGN);
         ExpressionClassifier rhs_classifier;
         ExpressionT rhs = this->ParseAssignmentExpression(
             true, &rhs_classifier, CHECK_OK_CUSTOM(EmptyObjectLiteralProperty));
@@ skipping 1525 matching lines @@
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PREPARSER_H