RegExp: Add support for the ES6-proposed sticky flag

src/jsregexp.h

Index: src/jsregexp.h
diff --git a/src/jsregexp.h b/src/jsregexp.h
index 300c0ef1386433427cdf311e28661df6e145efc9..05304a89d554bdea56c1274e46abcd15951885e3 100644
--- a/src/jsregexp.h
+++ b/src/jsregexp.h
@@ -1661,7 +1661,7 @@ class RegExpEngine: public AllStatic {
   };
 
   static CompilationResult Compile(RegExpCompileData* input, bool ignore_case,
-                                   bool global, bool multiline,
+                                   bool global, bool multiline, bool sticky,
                                    Handle<String> pattern,
                                    Handle<String> sample_subject,
                                    bool is_one_byte, Zone* zone);