Check for let in lexically bound names for short object literals

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index d890ae5c216d7b497d0f3801288bd2fe7c4123fb..433a94893720e78d71f946abbd9ffbfbd8b553dc 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -2648,6 +2648,10 @@ ParserBase<Traits>::ParsePropertyDefinition(
           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());