Mention upgrade of asm in 2.16.18

Change-Id: I181c5099d902a701fe541077a1c3b9e8312af0bd
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index 0dc9cc5..b342c67 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -866,6 +866,8 @@
 
     This allows to more easily support newer JDK versions.
 
+  * Upgrade asm to 7.2
+
   * [Issue 14242](https://bugs.chromium.org/p/gerrit/issues/detail?id=12424):
   Upgrade gwtjsonrpc to 1.12