the exception handler is dead cause NPE in unssa

fix https://github.com/pxb1988/dex2jar/issues/477

dex-ir/src/main/java/com/googlecode/dex2jar/ir/ts/UnSSATransformer.java

@@ -361,6 +361,8 @@ public class UnSSATransformer implements Transformer {
                 }
                 tos.clear();
             } else if (stmt.st == ST.LABEL) { //
+                // https://github.com/pxb1988/dex2jar/issues/477
+                // the exception handler is dead and stmt.frame is null
                 LabelStmt label = (LabelStmt) stmt;
                 if (label.phis != null) {
                     for (AssignStmt phiAssignStmt : (List<AssignStmt>) label.phis) {

dex-translator/src/main/java/com/googlecode/d2j/dex/Dex2Asm.java

@@ -646,7 +646,14 @@ public class Dex2Asm {
         T_multiArray.transform(irMethod);
         T_voidInvoke.transform(irMethod);
         T_type.transform(irMethod);
-        T_unssa.transform(irMethod);
+        {
+            // https://github.com/pxb1988/dex2jar/issues/477
+            // dead code found in unssa, clean up
+            T_deadCode.transform(irMethod);
+            T_removeLocal.transform(irMethod);
+            T_removeConst.transform(irMethod);
+            T_unssa.transform(irMethod);
+        }
         T_trimEx.transform(irMethod);
         T_ir2jRegAssign.transform(irMethod);
     }