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/text/NumberFormat.java

@@ -1258,6 +1258,7 @@ public abstract class NumberFormat extends Format  {
          *
          * @param name Name of the attribute
          */
+        @SuppressWarnings("this-escape")
         protected Field(String name) {
             super(name);
             if (this.getClass() == NumberFormat.Field.class) {