8325189: Enable this-escape javac warning in java.base

Reviewed-by: alanb, erikj, naoto, smarks, ihse, joehw, lancea, weijun

src/java.base/share/classes/java/io/ObjectInputStream.java

@@ -390,6 +390,7 @@ public class ObjectInputStream
      * @see     ObjectInputStream#readFields()
      * @see     ObjectOutputStream#ObjectOutputStream(OutputStream)
      */
+    @SuppressWarnings("this-escape")
     public ObjectInputStream(InputStream in) throws IOException {
         verifySubclass();
         bin = new BlockDataInputStream(in);