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/util/IdentityHashMap.java

@@ -273,6 +273,7 @@ public class IdentityHashMap<K,V>
      * @param m the map whose mappings are to be placed into this map
      * @throws NullPointerException if the specified map is null
      */
+    @SuppressWarnings("this-escape")
     public IdentityHashMap(Map<? extends K, ? extends V> m) {
         // Allow for a bit of growth
         this((int) ((1 + m.size()) * 1.1));