message: fix TypeAnalysisRuntimeAssert
  Summary:
  The code used to access `->insn` of an `MethodItemEntry`, even though it was not guaranteed to be of `->type` `MFLOW_OPCODE` after the last call to `insert_field_assert`.
  This is getting fixed here with an additional check.
diff: @@ -140,6 +140,11 @@ RuntimeAssertTransform::Stats RuntimeAssertTransform::apply(
  always_assert(it->insn);
  it = insert_field_assert(wps, method->get_class(), code,
  in_clinit_or_init, it, stats);
  + // Note that `it` may no longer point to an entry of type MFLOW_OPCODE, as
  + // it maybe of type MFLOW_TARGET
  + if (it->type != MFLOW_OPCODE) {
  + continue;
  + }
  it =
  insert_return_value_assert(wps, method->get_class(), code, it, stats);
  }
  