cleanup: make fields final

src/org/jetbrains/java/decompiler/modules/decompiler/FinallyProcessor.java

@@ -547,11 +547,11 @@ public class FinallyProcessor {
                                   Map<BasicBlock, Boolean> mapLast,
                                   boolean skippedFirst) {
     class BlockStackEntry {
-      public BasicBlock blockCatch;
-      public BasicBlock blockSample;
+      public final BasicBlock blockCatch;
+      public final BasicBlock blockSample;
 
       // TODO: correct handling (merging) of multiple paths
-      public List<int[]> lstStoreVars;
+      public final List<int[]> lstStoreVars;
 
       BlockStackEntry(BasicBlock blockCatch, BasicBlock blockSample, List<int[]> lstStoreVars) {
         this.blockCatch = blockCatch;

src/org/jetbrains/java/decompiler/modules/decompiler/deobfuscator/IrreducibleCFGDeobfuscator.java

@@ -16,7 +16,7 @@ public class IrreducibleCFGDeobfuscator {
   public static boolean isStatementIrreducible(Statement statement) {
 
     class Node {
-      public Integer id;
+      public final Integer id;
       public final Set<Node> preds = new HashSet<>();
       public final Set<Node> succs = new HashSet<>();
 

src/org/jetbrains/java/decompiler/modules/decompiler/sforms/FlattenStatementsHelper.java

@@ -56,9 +56,9 @@ public class FlattenStatementsHelper {
   private void flattenStatement() {
 
     class StatementStackEntry {
-      public Statement statement;
-      public LinkedList<StackEntry> stackFinally;
-      public List<Exprent> tailExprents;
+      public final Statement statement;
+      public final LinkedList<StackEntry> stackFinally;
+      public final List<Exprent> tailExprents;
 
       public int statementIndex;
       public int edgeIndex;