[regexp] Allow named captures and back-references in non-unicode patterns

src/regexp/regexp-parser.h

 // Copyright 2016 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_REGEXP_PARSER_H_
 #define V8_REGEXP_REGEXP_PARSER_H_
 
 #include "src/objects.h"
 #include "src/regexp/regexp-ast.h"
 #include "src/zone/zone.h"
@@ skipping 275 matching lines @@
   bool ParseNamedBackReference(RegExpBuilder* builder,
                                RegExpParserState* state);
 
   // After the initial parsing pass, patch corresponding RegExpCapture objects
   // into all RegExpBackReferences. This is done after initial parsing in order
   // to avoid complicating cases in which references comes before the capture.
   void PatchNamedBackReferences();
 
   Handle<FixedArray> CreateCaptureNameMap();
 
+  // Returns true iff the pattern contains named captures. May call
+  // ScanForCaptures to look ahead at the remaining pattern.
+  bool HasNamedCaptures();
+
   Isolate* isolate() { return isolate_; }
   Zone* zone() const { return zone_; }
 
   uc32 current() { return current_; }
   bool has_more() { return has_more_; }
   bool has_next() { return next_pos_ < in()->length(); }
   uc32 Next();
   template <bool update_position>
   uc32 ReadNext();
   FlatStringReader* in() { return in_; }
   void ScanForCaptures();
 
   Isolate* isolate_;
   Zone* zone_;
   Handle<String>* error_;
   ZoneList<RegExpCapture*>* captures_;
   ZoneList<RegExpCapture*>* named_captures_;
   ZoneList<RegExpBackReference*>* named_back_references_;
   FlatStringReader* in_;
   uc32 current_;
   bool dotall_;
   bool ignore_case_;
   bool multiline_;
   bool unicode_;
   int next_pos_;
   int captures_started_;
-  // The capture count is only valid after we have scanned for captures.
-  int capture_count_;
+  int capture_count_;  // Only valid after we have scanned for captures.
   bool has_more_;
   bool simple_;
   bool contains_anchor_;
   bool is_scanned_for_captures_;
+  bool has_named_captures_;  // Only valid after we have scanned for captures.
   bool failed_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_REGEXP_PARSER_H_