DiscardableZoneScope fix. It was an unintentional noop.

src/parsing/parser.cc

 // 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.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-rewriter.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 4425 matching lines @@
           !(FLAG_validate_asm && scope->asm_function());
       // Open a new zone scope, which sets our AstNodeFactory to allocate in the
       // new temporary zone if the preconditions are satisfied, and ensures that
       // the previous zone is always restored after parsing the body.
       // For the purpose of scope analysis, some ZoneObjects allocated by the
       // factory must persist after the function body is thrown away and
       // temp_zone is deallocated. These objects are instead allocated in a
       // parser-persistent zone (see parser_zone_ in AstNodeFactory).
       {
         Zone temp_zone(zone()->allocator());
-        DiscardableZoneScope(this, &temp_zone, use_temp_zone);
+        DiscardableZoneScope zone_scope(this, &temp_zone, use_temp_zone);
         body = ParseEagerFunctionBody(function_name, pos, formals, kind,
                                       function_type, CHECK_OK);
       }
       materialized_literal_count = function_state.materialized_literal_count();
       expected_property_count = function_state.expected_property_count();
       if (use_temp_zone) {
         // If the preconditions are correct the function body should never be
         // accessed, but do this anyway for better behaviour if they're wrong.
         body = NULL;
       }
@@ skipping 2617 matching lines @@
   node->Print(Isolate::Current());
 }
 #endif  // DEBUG
 
 #undef CHECK_OK
 #undef CHECK_OK_VOID
 #undef CHECK_FAILED
 
 }  // namespace internal
 }  // namespace v8