[regexp] Turn last match info into a simple FixedArray

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 61f738e0ac2dc3d001f0cb6ff7f4f2f438d89bb1..11bba2372b36a1e21c3574907fc56c0d01721ff8 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -10310,6 +10310,15 @@ Handle<ArrayList> ArrayList::EnsureSpace(Handle<ArrayList> array, int length) {
   return ret;
 }
 
+Handle<RegExpMatchInfo> RegExpMatchInfo::ReserveCaptures(
+    Handle<RegExpMatchInfo> match_info, int capture_count) {
+  DCHECK_GE(match_info->length(), kLastMatchOverhead);
+  const int required_length = kFirstCaptureIndex + capture_count;
+  Handle<FixedArray> result =
+      EnsureSpaceInFixedArray(match_info, required_length);
+  return Handle<RegExpMatchInfo>::cast(result);
+}
+
 // static
 Handle<FrameArray> FrameArray::AppendJSFrame(Handle<FrameArray> in,
                                              Handle<Object> receiver,