[regexp] clear QuickCheckDetails for backward reads.

src/regexp/jsregexp.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_REGEXP_JSREGEXP_H_
 #define V8_REGEXP_JSREGEXP_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 
@@ skipping 1096 matching lines @@
                    Trace* trace,
                    PreloadState* preloads);
   DispatchTable* table_;
   // If true, this node is never checked at the start of the input.
   // Allows a new trace to start with at_start() set to false.
   bool not_at_start_;
   bool being_calculated_;
 };
 
 
-class NegativeLookaheadChoiceNode: public ChoiceNode {
+class NegativeLookaroundChoiceNode : public ChoiceNode {
  public:
-  explicit NegativeLookaheadChoiceNode(GuardedAlternative this_must_fail,
-                                       GuardedAlternative then_do_this,
-                                       Zone* zone)
+  explicit NegativeLookaroundChoiceNode(GuardedAlternative this_must_fail,
+                                        GuardedAlternative then_do_this,
+                                        Zone* zone)
       : ChoiceNode(2, zone) {
     AddAlternative(this_must_fail);
     AddAlternative(then_do_this);
   }
   virtual int EatsAtLeast(int still_to_find, int budget, bool not_at_start);
   virtual void GetQuickCheckDetails(QuickCheckDetails* details,
                                     RegExpCompiler* compiler,
                                     int characters_filled_in,
                                     bool not_at_start);
   virtual void FillInBMInfo(Isolate* isolate, int offset, int budget,
@@ skipping 546 matching lines @@
   static const int kStringOffset = 0;
   static const int kPatternOffset = 1;
   static const int kArrayOffset = 2;
   static const int kLastMatchOffset = 3;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_JSREGEXP_H_