[parser] early error when declaration Pattern missing Initializer

src/preparser.cc

Index: src/preparser.cc
diff --git a/src/preparser.cc b/src/preparser.cc
index 74e11b1d454b3b33a3f6bcadb18f91476a246f37..246b03a016133abae830abe1f9c02464e20f3baf 100644
--- a/src/preparser.cc
+++ b/src/preparser.cc
@@ -580,6 +580,7 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
     // Parse binding pattern.
     if (nvars > 0) Consume(Token::COMMA);
     {
+      int decl_pos = peek_position();
       ExpressionClassifier pattern_classifier;
       Token::Value next = peek();
       PreParserExpression pattern =
@@ -594,6 +595,20 @@ PreParser::Statement PreParser::ParseVariableDeclarations(
         *ok = false;
         return Statement::Default();
       }
+
+      bool is_for_iteration_variable =
+          var_context == kForStatement &&
+          (peek() == Token::IN || PeekContextualKeyword(CStrVector("of")));
+
+      if (!is_for_iteration_variable &&
+          (pattern.IsObjectLiteral() || pattern.IsArrayLiteral()) &&
+          peek() != Token::ASSIGN) {
+        ReportMessageAt(
+            Scanner::Location(decl_pos, scanner()->location().end_pos),
+            MessageTemplate::kInvalidDestructuringDeclaration);
+        *ok = false;
+        return Statement::Default();
+      }
     }
 
     Scanner::Location variable_loc = scanner()->location();