BUG: 1.3.0rc1 pd.util.hash_array on Index fails to access _values_for_factorize
- [X] I have checked that this issue has not already been reported.

- [ ] I have confirmed this bug exists on the latest version of pandas. (does not exist in 1.2.4, only seen in 1.3.0rc1 and master)

- [X] (optional) I have confirmed this bug exists on the master branch of pandas. (confirmed on 0b68d87a443)

---


#### Code Sample, a copy-pastable example

```python
In [1]: import pandas as pd

In [2]: pd.util.hash_array(pd.DatetimeIndex(['2018-10-28 01:20:00'], tz='Europe/Berlin'))
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-2-389898c5af02> in <module>
----> 1 pd.util.hash_array(pd.DatetimeIndex(['2018-10-28 01:20:00'], tz='Europe/Berlin'))

~/working_dir/pandas/pandas/core/util/hashing.py in hash_array(vals, encoding, hash_key, categorize)
    287     elif not isinstance(vals, np.ndarray):
    288         # i.e. ExtensionArray
--> 289         vals, _ = vals._values_for_factorize()
    290 
    291     return _hash_ndarray(vals, encoding, hash_key, categorize)

AttributeError: 'DatetimeIndex' object has no attribute '_values_for_factorize'

In [3]: pd.util.hash_array(pd.Index([1,2,3]))
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-3-e66efa244441> in <module>
----> 1 pd.util.hash_array(pd.Index([1,2,3]))

~/working_dir/pandas/pandas/core/util/hashing.py in hash_array(vals, encoding, hash_key, categorize)
    287     elif not isinstance(vals, np.ndarray):
    288         # i.e. ExtensionArray
--> 289         vals, _ = vals._values_for_factorize()
    290 
    291     return _hash_ndarray(vals, encoding, hash_key, categorize)

AttributeError: 'Int64Index' object has no attribute '_values_for_factorize'

In [4]: pd.util.hash_array(pd.RangeIndex(1,3))
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-af0900aae979> in <module>
----> 1 pd.util.hash_array(pd.RangeIndex(1,3))

~/working_dir/pandas/pandas/core/util/hashing.py in hash_array(vals, encoding, hash_key, categorize)
    287     elif not isinstance(vals, np.ndarray):
    288         # i.e. ExtensionArray
--> 289         vals, _ = vals._values_for_factorize()
    290 
    291     return _hash_ndarray(vals, encoding, hash_key, categorize)

AttributeError: 'RangeIndex' object has no attribute '_values_for_factorize'
```

#### Problem description

This issue looks similar to https://github.com/pandas-dev/pandas/issues/41817, but that is specifically for DateTimeIndex with tz defined, while this seems to happen for any Index instance.

#### Expected Output

A hash of the input index, as in pandas < 1.3.0.

#### Output of ``pd.show_versions()``

<details>
INSTALLED VERSIONS      
------------------      
commit           : 2dd9e9ba9009a40191c0c0b96262fa3939d609f0
python           : 3.8.6.final.0
python-bits      : 64   
OS               : Linux 
OS-release       : 5.10.28-1rodete1-amd64
Version          : #1 SMP Debian 5.10.28-1rodete1 (2021-04-30)
machine          : x86_64
processor        : 
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.3.0rc1
numpy            : 1.19.5
pytz             : 2021.1
dateutil         : 2.8.1
pip              : 20.2.1
setuptools       : 49.2.1
Cython           : 0.29.22
pytest           : 6.2.2
hypothesis       : 6.4.0
sphinx           : 3.5.1
blosc            : 1.10.2
feather          : None
xlsxwriter       : 1.3.7
lxml.etree       : 4.6.2
html5lib         : 1.1
pymysql          : None
psycopg2         : None
jinja2           : 2.11.3
IPython          : 7.21.0
pandas_datareader: None
bs4              : 4.9.3
bottleneck       : 1.3.2
fsspec           : 0.8.7
fastparquet      : 0.5.0
gcsfs            : 0.7.2
matplotlib       : 3.3.4
numexpr          : 2.7.3
odfpy            : None
openpyxl         : 3.0.6
pandas_gbq       : None
pyarrow          : 3.0.0
pyxlsb           : None
s3fs             : 0.5.2
scipy            : 1.6.1
sqlalchemy       : 1.3.23
tables           : 3.6.1
tabulate         : 0.8.9
xarray           : 0.17.0
xlrd             : 2.0.1
xlwt             : 1.3.0
numba            : 0.52.0
</details>
