Implement flag and source getters on RegExp.prototype.

src/js/string.js

Index: src/js/string.js
diff --git a/src/js/string.js b/src/js/string.js
index 0fdd7ae342f88225165304c25920a4ba574445f2..33ac96577e701e94899057909abbb27cec0aeae3 100644
--- a/src/js/string.js
+++ b/src/js/string.js
@@ -19,6 +19,7 @@ var MakeRangeError;
 var MakeTypeError;
 var RegExpExec;
 var RegExpExecNoTests;
+var regExpFlagsSymbol = utils.ImportNow("regexp_flags_symbol");
 var RegExpLastMatchInfo;
 
 utils.Import(function(from) {
@@ -155,7 +156,7 @@ function StringMatchJS(regexp) {
 
   var subject = TO_STRING(this);
   if (IS_REGEXP(regexp)) {
-    if (!regexp.global) return RegExpExecNoTests(regexp, subject, 0);
+    if (!REGEXP_GLOBAL(regexp)) return RegExpExecNoTests(regexp, subject, 0);
     var result = %StringMatch(subject, regexp, RegExpLastMatchInfo);
     regexp.lastIndex = 0;
     return result;
@@ -225,7 +226,7 @@ function StringReplace(search, replace) {
     if (!IS_CALLABLE(replace)) {
       replace = TO_STRING(replace);
 
-      if (!search.global) {
+      if (!REGEXP_GLOBAL(search)) {
         // Non-global regexp search, string replace.
         var match = RegExpExec(search, subject, 0);
         if (match == null) {
@@ -247,7 +248,7 @@ function StringReplace(search, replace) {
           subject, search, replace, RegExpLastMatchInfo);
     }
 
-    if (search.global) {
+    if (REGEXP_GLOBAL(search)) {
       // Global regexp search, function replace.
       return StringReplaceGlobalRegExpWithFunction(subject, search, replace);
     }