[string] Fix error message in String.prototype.repeat.

R=yangguo@chromium.org
TEST=message/regress/regress-crbug-691194
BUG=chromium:691194

Change-Id: I72198e087f88abf89cdd38b99c19e10cbebda08d
Reviewed-on: https://chromium-review.googlesource.com/445942Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43480}

src/js/string.js

@@ -220,7 +220,7 @@ function StringRepeat(count) {
 
   // The maximum string length is stored in a smi, so a longer repeat
   // must result in a range error.
-  if (n > %_MaxSmi()) throw %make_range_error(kInvalidCountValue);
+  if (n > %_MaxSmi()) throw %make_range_error(kInvalidStringLength);
 
   var r = "";
   while (true) {

test/message/regress/regress-crbug-691194.js

+// Copyright 2017 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.
+
+"foo".repeat(1 << 30)

test/message/regress/regress-crbug-691194.out

+# Copyright 2017 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.
+
+*%(basename)s:5: RangeError: Invalid string length
+"foo".repeat(1 << 30)
+      ^
+RangeError: Invalid string length
+    at String.repeat (native)
+    at *%(basename)s:5:7