message: [ssa::verifier] Ignore arity of `MOpcode::OpCustom`
diff: @@ -191,7 +191,9 @@ impl Verify for SSAStorage {
  MArity::Ternary => 3,
  };
  - if opcode != MOpcode::OpCall {
  + if opcode != MOpcode::OpCall
  + && opcode.idx() != MOpcode::OpCustom(String::new()).idx()
  + {
  check!(op_len == n, SSAErr::WrongNumOperands(*exi, n, op_len));
  }
  