decompiler: removeLast helper to avoid possible errors

src/org/jetbrains/java/decompiler/code/InstructionSequence.java

@@ -81,6 +81,12 @@ public abstract class InstructionSequence {
     collinstr.remove(index);
   }
 
+  public void removeLast() {
+    if (!collinstr.isEmpty()) {
+      collinstr.remove(collinstr.size() - 1);
+    }
+  }
+
   public Instruction getCurrentInstr() {
     return collinstr.get(pointer);
   }

src/org/jetbrains/java/decompiler/modules/code/DeadCodeHelper.java

@@ -252,7 +252,7 @@ public class DeadCodeHelper {
       Instruction instr = block.getLastInstruction();
 
       if (instr != null && instr.opcode == CodeConstants.opc_goto) {
-        block.getSeq().removeInstruction(block.getSeq().length() - 1);
+        block.getSeq().removeLast();
       }
     }
 

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

@@ -863,11 +863,11 @@ public class FinallyProcessor {
 
       if ((type & 2) > 0) { // last
         if (finallytype == 0 || finallytype == 2) {
-          seqPattern.removeInstruction(seqPattern.length() - 1);
+          seqPattern.removeLast();
         }
 
         if (finallytype == 2) {
-          seqPattern.removeInstruction(seqPattern.length() - 1);
+          seqPattern.removeLast();
         }
       }
     }
@@ -1078,11 +1078,11 @@ public class FinallyProcessor {
 
       if ((blocktype & 2) > 0) { // last
         if (finallytype == 2 || finallytype == 0) {
-          seq.removeInstruction(seq.length() - 1);
+          seq.removeLast();
         }
 
         if (finallytype == 2) { // astore
-          seq.removeInstruction(seq.length() - 1);
+          seq.removeLast();
         }
       }
     }