Allow String to be compiled by Javac

Change-Id: I16a3355246fee7a2b3d48bb0a20af7da990152ea

user/super/com/google/gwt/emul/java/lang/String.java

diff --git a/user/super/com/google/gwt/emul/java/lang/String.java b/user/super/com/google/gwt/emul/java/lang/String.java
index 37cab11..825faa6 100644
--- a/user/super/com/google/gwt/emul/java/lang/String.java
+++ b/user/super/com/google/gwt/emul/java/lang/String.java
@@ -34,7 +34,8 @@
 /**
  * Intrinsic string class.
  */
-
+// Needed to have constructors not fail compilation internally at Google
+@SuppressWarnings("ReturnValueIgnored")
 public final class String implements Comparable<String>, CharSequence,
     Serializable {
   /* TODO(jat): consider whether we want to support the following methods;