Benchmark for indexing with .loc for sorted/unsorted DatetimeIndex
- [ ] closes #38690 
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

thanks @weikhor  @weikhor this looks like it's failing on the main branch, could you push another PR to fix?

```
2T02:52:46.5036611Z ##[error][ 20.22%] ··· indexing.DatetimeIndexIndexing.time_loc_sorted              failed
2022-03-02T02:52:46.5037899Z [ 20.22%] ···· Traceback (most recent call last):
2022-03-02T02:52:46.5038316Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/base.py", line 3738, in get_loc
2022-03-02T02:52:46.5038698Z                    return self._engine.get_loc(casted_key)
2022-03-02T02:52:46.5039115Z                  File "pandas/_libs/index.pyx", line 516, in pandas._libs.index.DatetimeEngine.get_loc
2022-03-02T02:52:46.5039798Z                  File "pandas/_libs/index.pyx", line 545, in pandas._libs.index.DatetimeEngine.get_loc
2022-03-02T02:52:46.5040514Z                  File "pandas/_libs/index.pyx", line 197, in pandas._libs.index.IndexEngine._get_loc_duplicates
2022-03-02T02:52:46.5040908Z                KeyError: 1465628400000000000
2022-03-02T02:52:46.5041148Z                
2022-03-02T02:52:46.5041464Z                The above exception was the direct cause of the following exception:
2022-03-02T02:52:46.5041769Z                
2022-03-02T02:52:46.5042039Z                Traceback (most recent call last):
2022-03-02T02:52:46.5042561Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/datetimes.py", line 680, in get_loc
2022-03-02T02:52:46.5042976Z                    return Index.get_loc(self, key, method, tolerance)
2022-03-02T02:52:46.5043366Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/base.py", line 3740, in get_loc
2022-03-02T02:52:46.5043737Z                    raise KeyError(key) from err
2022-03-02T02:52:46.5044212Z                KeyError: Timestamp('2016-06-11 00:00:00-0700', tz='US/Pacific')
2022-03-02T02:52:46.5044492Z                
2022-03-02T02:52:46.5044816Z                The above exception was the direct cause of the following exception:
2022-03-02T02:52:46.5045122Z                
2022-03-02T02:52:46.5045378Z                Traceback (most recent call last):
2022-03-02T02:52:46.5045979Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 1184, in main_run_server
2022-03-02T02:52:46.5046378Z                    main_run(run_args)
2022-03-02T02:52:46.5046943Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 1058, in main_run
2022-03-02T02:52:46.5047358Z                    result = benchmark.do_run()
2022-03-02T02:52:46.5047909Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 537, in do_run
2022-03-02T02:52:46.5048333Z                    return self.run(*self._current_params)
2022-03-02T02:52:46.5048912Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 627, in run
2022-03-02T02:52:46.5049361Z                    samples, number = self.benchmark_timing(timer, min_repeat, max_repeat,
2022-03-02T02:52:46.5050123Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 694, in benchmark_timing
2022-03-02T02:52:46.5050549Z                    timing = timer.timeit(number)
2022-03-02T02:52:46.5051075Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/timeit.py", line 177, in timeit
2022-03-02T02:52:46.5051442Z                    timing = self.inner(it, self.timer)
2022-03-02T02:52:46.5051836Z                  File "<timeit-src>", line 6, in inner
2022-03-02T02:52:46.5052235Z                  File "/home/runner/work/pandas/pandas/asv_bench/benchmarks/indexing.py", line 309, in time_loc_sorted
2022-03-02T02:52:46.5052701Z                    self.df_sort.loc["2016-6-11"]
2022-03-02T02:52:46.5053069Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1048, in __getitem__
2022-03-02T02:52:46.5053481Z                    return self._getitem_axis(maybe_callable, axis=axis)
2022-03-02T02:52:46.5053904Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1284, in _getitem_axis
2022-03-02T02:52:46.6076973Z                    return self._get_label(key, axis=axis)
2022-03-02T02:52:46.6077429Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1235, in _get_label
2022-03-02T02:52:46.6077820Z                    return self.obj.xs(label, axis=axis)
2022-03-02T02:52:46.6078203Z                  File "/home/runner/work/pandas/pandas/pandas/core/generic.py", line 3859, in xs
2022-03-02T02:52:46.6078543Z                    loc = index.get_loc(key)
2022-03-02T02:52:46.6078920Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/datetimes.py", line 682, in get_loc
2022-03-02T02:52:46.6079763Z                    raise KeyError(orig_key) from err
2022-03-02T02:52:46.6080503Z                KeyError: '2016-6-11'
2022-03-02T02:52:46.6080638Z 
2022-03-02T02:52:46.6081608Z ##[error][ 20.27%] ··· ...xing.DatetimeIndexIndexing.time_loc_unsorted             failed
2022-03-02T02:52:46.6082751Z [ 20.27%] ···· Traceback (most recent call last):
2022-03-02T02:52:46.6083105Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/base.py", line 3738, in get_loc
2022-03-02T02:52:46.6083465Z                    return self._engine.get_loc(casted_key)
2022-03-02T02:52:46.6083840Z                  File "pandas/_libs/index.pyx", line 516, in pandas._libs.index.DatetimeEngine.get_loc
2022-03-02T02:52:46.6084281Z                  File "pandas/_libs/index.pyx", line 545, in pandas._libs.index.DatetimeEngine.get_loc
2022-03-02T02:52:46.6084718Z                  File "pandas/_libs/index.pyx", line 203, in pandas._libs.index.IndexEngine._get_loc_duplicates
2022-03-02T02:52:46.6085181Z                  File "pandas/_libs/index.pyx", line 211, in pandas._libs.index.IndexEngine._maybe_get_bool_indexer
2022-03-02T02:52:46.6085606Z                  File "pandas/_libs/index.pyx", line 107, in pandas._libs.index._unpack_bool_indexer
2022-03-02T02:52:46.6085928Z                KeyError: 1465628400000000000
2022-03-02T02:52:46.6086134Z                
2022-03-02T02:52:46.6086427Z                The above exception was the direct cause of the following exception:
2022-03-02T02:52:46.6086705Z                
2022-03-02T02:52:46.6086931Z                Traceback (most recent call last):
2022-03-02T02:52:46.6087296Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/datetimes.py", line 680, in get_loc
2022-03-02T02:52:46.6087679Z                    return Index.get_loc(self, key, method, tolerance)
2022-03-02T02:52:46.6088052Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/base.py", line 3740, in get_loc
2022-03-02T02:52:46.6088379Z                    raise KeyError(key) from err
2022-03-02T02:52:46.6088793Z                KeyError: Timestamp('2016-06-11 00:00:00-0700', tz='US/Pacific')
2022-03-02T02:52:46.6089054Z                
2022-03-02T02:52:46.6089329Z                The above exception was the direct cause of the following exception:
2022-03-02T02:52:46.6089607Z                
2022-03-02T02:52:46.6089982Z                Traceback (most recent call last):
2022-03-02T02:52:46.6090549Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 1184, in main_run_server
2022-03-02T02:52:46.6090904Z                    main_run(run_args)
2022-03-02T02:52:46.6091419Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 1058, in main_run
2022-03-02T02:52:46.6091793Z                    result = benchmark.do_run()
2022-03-02T02:52:46.6092301Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 537, in do_run
2022-03-02T02:52:46.6092695Z                    return self.run(*self._current_params)
2022-03-02T02:52:46.6093220Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 627, in run
2022-03-02T02:52:46.6093651Z                    samples, number = self.benchmark_timing(timer, min_repeat, max_repeat,
2022-03-02T02:52:46.6094239Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/site-packages/asv/benchmark.py", line 694, in benchmark_timing
2022-03-02T02:52:46.6094625Z                    timing = timer.timeit(number)
2022-03-02T02:52:46.6095105Z                  File "/usr/share/miniconda/envs/pandas-dev/lib/python3.8/timeit.py", line 177, in timeit
2022-03-02T02:52:46.6095458Z                    timing = self.inner(it, self.timer)
2022-03-02T02:52:46.6095805Z                  File "<timeit-src>", line 6, in inner
2022-03-02T02:52:46.6096180Z                  File "/home/runner/work/pandas/pandas/asv_bench/benchmarks/indexing.py", line 306, in time_loc_unsorted
2022-03-02T02:52:46.6096708Z                    self.df.loc["2016-6-11"]
2022-03-02T02:52:46.6097052Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1048, in __getitem__
2022-03-02T02:52:46.6097415Z                    return self._getitem_axis(maybe_callable, axis=axis)
2022-03-02T02:52:46.6097804Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1284, in _getitem_axis
2022-03-02T02:52:46.6098159Z                    return self._get_label(key, axis=axis)
2022-03-02T02:52:46.6098502Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexing.py", line 1235, in _get_label
2022-03-02T02:52:46.6098850Z                    return self.obj.xs(label, axis=axis)
2022-03-02T02:52:46.6099196Z                  File "/home/runner/work/pandas/pandas/pandas/core/generic.py", line 3859, in xs
2022-03-02T02:52:55.5493277Z                    loc = index.get_loc(key)
2022-03-02T02:52:55.5494144Z                  File "/home/runner/work/pandas/pandas/pandas/core/indexes/datetimes.py", line 682, in get_loc
2022-03-02T02:52:55.5494680Z                    raise KeyError(orig_key) from err
2022-03-02T02:52:55.5495421Z                KeyError: '2016-6-11'
``` oo no. My bad. I make change to this as soon as possible. 