perf tuning of `BaseRow`

perf tuning of `BaseRow`

common cases are a bit faster overall

Python version
|                      | python opt | python main | py opt / main |
| -------------------- | ---------- | ----------- | ------------- |
| base_row_new         | 0.84959    | 0.86417     | 0.9831283197  |
| row_new              | 0.85698    | 0.85543     | 1.001811954   |
| base_row_new_proc    | 2.77489    | 2.81795     | 0.9847193882  |
| row_new_proc         | 2.77881    | 2.86206     | 0.9709125595  |
| brow_new_proc_none   | 1.6311     | 1.65773     | 0.9839358641  |
| row_new_proc_none    | 1.65048    | 1.69896     | 0.9714648962  |
| row_dumps            | 0.15279    | 0.14519     | 1.052345203   |
| row_loads            | 0.91471    | 0.91358     | 1.001236892   |
| row_values_impl      | 0.1818     | 0.17773     | 1.022899904   |
| row_iter             | 0.44042    | 0.4554      | 0.967105841   |
| row_len              | 0.13858    | 0.13079     | 1.059561129   |
| row_hash             | 0.28614    | 0.29172     | 0.9808720691  |
| getitem              | 0.23159    | 0.23138     | 1.000907598   |
| getitem_slice        | 0.38393    | 0.38765     | 0.9904037147  |
| get_by_key           | 0.33692    | 0.33913     | 0.993483325   |
| get_by_key2          | 0.35105    | 0.33915     | 1.035087719   |
| getattr              | 0.46809    | 0.46911     | 0.9978256699  |
| get_by_key_recreate  | 1.08137    | 1.18224     | 0.9146789146  |
| get_by_key_recreate2 | 0.98543    | 0.99272     | 0.9926565396  |
| getattr_recreate     | 0.74       | 0.7407      | 0.999054948   |
| contains             | 0.49312    | 0.74477     | 0.6621104502  |

Cython version
|                      | cython opt | cython main | cy opt / main |
| -------------------- | ---------- | ----------- | ------------- |
| base_row_new         | 0.12933    | 0.1347      | 0.9601336303  |
| row_new              | 0.15755    | 0.16489     | 0.9554854752  |
| base_row_new_proc    | 0.87398    | 1.08483     | 0.8056377497  |
| row_new_proc         | 0.88592    | 1.13255     | 0.7822347799  |
| brow_new_proc_none   | 0.2664     | 0.41703     | 0.6388029638  |
| row_new_proc_none    | 0.27526    | 0.42483     | 0.6479297601  |
| row_dumps            | 0.37526    | 0.20093     | 1.867615588   |
| row_loads            | 0.53037    | 0.3607      | 1.470390907   |
| row_values_impl      | 0.36886    | 0.22218     | 1.660185435   |
| row_iter             | 0.25249    | 0.25553     | 0.9881031581  |
| row_len              | 0.05194    | 0.05412     | 0.9597191426  |
| row_hash             | 0.18864    | 0.18726     | 1.007369433   |
| getitem              | 0.13876    | 0.13934     | 0.9958375197  |
| getitem_slice        | 0.23181    | 0.2318      | 1.000043141   |
| get_by_key           | 0.17031    | 0.17857     | 0.9537436299  |
| get_by_key2          | 0.58172    | 0.31651     | 1.837919813   |
| getattr              | 0.21275    | 1.16669     | 0.1823534958  |
| get_by_key_recreate  | 0.80161    | 0.8836      | 0.9072091444  |
| get_by_key_recreate2 | 1.14649    | 0.98709     | 1.161484768   |
| getattr_recreate     | 0.55927    | 1.09921     | 0.5087926784  |
| contains             | 0.35338    | 0.5494      | 0.6432107754  |

Closes: #12919
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/12919
Pull-request-sha: b13204b7416083ccff09a45291b11fd606ff0fbd

Change-Id: I5ff2b951f9840e99abdad3ae286ecb8becc70e4b