message: simplify normalize_overridden_method_withouts_sbs
  Summary: I don't understand why we'd ever want to insert the new source block *after* the first non-loading instruction in the entry block. This is simpler and makes more sense to me.
diff: @@ -996,27 +996,20 @@ struct SBHelper {
  reset_sb(*new_sb, overridden_method, SourceBlock::kSyntheticId);
  auto it = block->get_first_insn();
  - if (it == block->end()) {
  - block->insert_before(block->begin(), std::move(new_sb));
  - } else {
  - if (opcode::is_a_move_result(it->insn->opcode())) {
  + if (it != block->end() &&
  + opcode::is_move_result_any(it->insn->opcode())) {
  block->insert_after(it, std::move(new_sb));
  } else {
  block->insert_before(it, std::move(new_sb));
  }
  }
  - }
  auto* block = cfg->entry_block();
  auto new_sb = std::make_unique<SourceBlock>(*arbitrary_sb);
  // Bit weird, but better than making up real numbers.
  reset_sb(*new_sb, overridden_method, SourceBlock::kSyntheticId);
  auto it = block->get_first_non_param_loading_insn();
  - if (it == block->end()) {
  block->insert_before(it, std::move(new_sb));
  - } else {
  - block->insert_after(it, std::move(new_sb));
  - }
  }
  std::unique_ptr<SourceBlock> gen_arbitrary_reset_sb() {
  