message: Implement stack cleanup in br/br_if instructions
diff: @@ -271,8 +271,12 @@ execution_result execute(Instance& instance, FuncIdx function, std::vector<uint6
  pc = label.pc;
  immediates = label.immediate;
  - // FIXME: handle arity + stack_height ?
  - assert(stack.size() == label.stack_height);
  + // FIXME: handle arity
  + assert(label.arity == 0);
  +
  + // When branch is taken, additional stack items must be dropped.
  + assert(stack.size() >= label.stack_height);
  + stack.resize(label.stack_height);
  break;
  }
  case Instr::call:
  