A few misc code simplifications

PiperOrigin-RevId: 568278848

Author: blickly

src/com/google/javascript/jscomp/RewriteClassMembers.java

@@ -441,7 +441,7 @@ private static final class ClassRecord {
     final Node insertionPointBeforeClass;
 
     // Keeps track of the last statement inserted after the class
-    Node insertionPointAfterClass;
+    final Node insertionPointAfterClass;
 
     ClassRecord(Node classNode, Node classNameNode, Node classInsertionPoint) {
       this.classNode = classNode;