Make native NativeRegExp to refer to the iframe instance.

By doing this we avoid an JIT bug in MS Edge 11 and possibly improve
performance in some browsers.

Bug: #9458
Bug-Link: https://github.com/gwtproject/gwt/issues/9458
Change-Id: If6e44eac8aa5664938d4e2c5f39e629f65630663
diff --git a/user/super/com/google/gwt/emul/javaemul/internal/NativeRegExp.java b/user/super/com/google/gwt/emul/javaemul/internal/NativeRegExp.java
index e536763..6f7ca76 100644
--- a/user/super/com/google/gwt/emul/javaemul/internal/NativeRegExp.java
+++ b/user/super/com/google/gwt/emul/javaemul/internal/NativeRegExp.java
@@ -15,13 +15,12 @@
  */
 package javaemul.internal;
 
-import jsinterop.annotations.JsPackage;
 import jsinterop.annotations.JsType;
 
 /**
  * Simple class to work with native js regular expressions.
  */
-@JsType(isNative = true, name = "RegExp", namespace = JsPackage.GLOBAL)
+@JsType(isNative = true, name = "RegExp", namespace = "<window>")
 public class NativeRegExp {
   public int lastIndex;
   public NativeRegExp(String regex) { }