[regexp] quantifier refers to the surrogate pair in unicode regexp.

test/cctest/test-regexp.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 291 matching lines @@
   CheckParseEq("\\x34", "'\x34'");
   CheckParseEq("\\x60", "'\x60'");
   CheckParseEq("\\x3z", "'x3z'");
   CheckParseEq("\\c", "'\\c'");
   CheckParseEq("\\u0034", "'\x34'");
   CheckParseEq("\\u003z", "'u003z'");
   CheckParseEq("foo[z]*", "(: 'foo' (# 0 - g [z]))");
 
   // Unicode regexps
   CheckParseEq("\\u{12345}", "'\\ud808\\udf45'", true);
-  CheckParseEq("\\u{12345}\\u{23456}", "'\\ud808\\udf45\\ud84d\\udc56'", true);
+  CheckParseEq("\\u{12345}\\u{23456}", "(! '\\ud808\\udf45' '\\ud84d\\udc56')",
+               true);
   CheckParseEq("\\u{12345}|\\u{23456}", "(| '\\ud808\\udf45' '\\ud84d\\udc56')",
                true);
+  CheckParseEq("\\u{12345}{3}", "(# 3 3 g '\\ud808\\udf45')", true);
+  CheckParseEq("\\u{12345}*", "(# 0 - g '\\ud808\\udf45')", true);
 
   CHECK_SIMPLE("", false);
   CHECK_SIMPLE("a", true);
   CHECK_SIMPLE("a|b", false);
   CHECK_SIMPLE("a\\n", false);
   CHECK_SIMPLE("^a", false);
   CHECK_SIMPLE("a$", false);
   CHECK_SIMPLE("a\\b!", false);
   CHECK_SIMPLE("a\\Bb", false);
   CHECK_SIMPLE("a*", false);
@@ skipping 1603 matching lines @@
   // .toString() throws on non-RegExps that aren't RegExp.prototype
   v8::Local<v8::Value> resultToStringError = CompileRun(
       "var exception;"
       "try { RegExp.prototype.toString.call(null) }"
       "catch (e) { exception = e; }"
       "exception");
   CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeStickyGetter]);
   CHECK_EQ(1, use_counts[v8::Isolate::kRegExpPrototypeToString]);
   CHECK(resultToStringError->IsObject());
 }