Remove empty try-catch blocks in DCE

Signed-off-by: Major <major@emulate.rs>

asm/src/main/java/dev/openrs2/asm/InsnNodeUtils.kt

@@ -9,6 +9,7 @@ import org.objectweb.asm.tree.LabelNode
 import org.objectweb.asm.tree.LdcInsnNode
 import org.objectweb.asm.tree.LookupSwitchInsnNode
 import org.objectweb.asm.tree.TableSwitchInsnNode
+import org.objectweb.asm.tree.TryCatchBlockNode
 import org.objectweb.asm.util.Textifier
 import org.objectweb.asm.util.TraceMethodVisitor
 import java.io.PrintWriter
@@ -306,3 +307,16 @@ fun AbstractInsnNode.toPrettyString(): String {
         }
     }
 }
+
+fun TryCatchBlockNode.isBodyEmpty(): Boolean {
+    var current = start.next
+
+    while (true) {
+        when {
+            current == null -> return false
+            current === end -> return true
+            current.opcode != -1 -> return false
+            else -> current = current.next
+        }
+    }
+}

asm/src/main/java/dev/openrs2/asm/MethodNodeUtils.kt

@@ -125,7 +125,9 @@ fun MethodNode.removeDeadCode(owner: String) {
             }
         }
 
-        changed = changed or tryCatchBlocks.removeIf { it.start in deadLabels && it.end in deadLabels }
+        changed = changed or tryCatchBlocks.removeIf {
+            it.start in deadLabels && it.end in deadLabels || it.isBodyEmpty()
+        }
     } while (changed)
 }