Add Proxy support.

From-SVN: r57635

libjava/testsuite/libjava.lang/utf8concat.java

@@ -0,0 +1,11 @@
+public class utf8concat
+{
+  private static String s;
+
+  public static void main (String[] args)
+  {
+    // This causes a crash at runtime because the compiler is
+    // producing an invalid UTF-8 string literal.
+    s = "abc" + (char)183;
+  }
+}