PreParsing inner functions: Fix declaration-only variables.

src/parsing/preparser.cc

 // Copyright 2011 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.
 
 #include <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
@@ skipping 213 matching lines @@
     // Setting the Zone is necessary because zone_ might be the temp Zone, and
     // AstValueFactory doesn't know about it.
     factory.set_zone(zone());
     DCHECK_NOT_NULL(name.string_);
     scope()->NewUnresolved(&factory, name.string_, start_position, end_position,
                            NORMAL_VARIABLE);
   }
   return PreParserExpression::FromIdentifier(name);
 }
 
+void PreParser::DeclareAndInitializeVariables(
+    PreParserStatement block,
+    const DeclarationDescriptor* declaration_descriptor,
+    const DeclarationParsingResult::Declaration* declaration,
+    ZoneList<const AstRawString*>* names, bool* ok) {
+  if (declaration->pattern.string_) {
+    /* Mimic what Parser does when declaring variables (see
+       Parser::PatternRewriter::VisitVariableProxy).
+
+       var + no initializer -> RemoveUnresolved
+       let + no initializer -> RemoveUnresolved
+       var + initializer -> RemoveUnresolved followed by NewUnresolved
+       let + initializer -> RemoveUnresolved
+    */
+
+    if (declaration->initializer.IsEmpty() ||
+        declaration_descriptor->mode == VariableMode::LET) {
+      declaration_descriptor->scope->RemoveUnresolved(
+          declaration->pattern.string_);
+    }
+  }
+}
+
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 
 
 }  // namespace internal
 }  // namespace v8