pandas.DataFrame.reindex_like throws if called from a derived class instance
#### Code Sample, a copy-pastable example if possible

```python
import pandas as pd
import pandas.testing as pdt

class MyDataFrame(pd.DataFrame):
    pass

mdf = MyDataFrame()
df = pd.DataFrame()
# In DataFrame.reindex_like, the derived class is compared to
# the base class. The following line will throw
# 'AssertionError: <class 'pandas.core.frame.DataFrame'>'
mdf.reindex_like(df)

# In pdt.assert_frame_equal,
# check_like=True triggers a call to DataFrame.reindex_like.
# The following line will throw the same
# 'AssertionError: <class 'pandas.core.frame.DataFrame'>'
pdt.assert_frame_equal(mdf, df, check_like=True)
```
#### Problem description

The method `reindex_like` throws an `AssertionError` when the caller is an instance of a derived class of `pandas.DataFrame`.

#### Expected Output

No exception thrown.

#### Output of ``pd.show_versions()``
INSTALLED VERSIONS
------------------
commit           : None
python           : 3.6.9.final.0
python-bits      : 64
OS               : Linux
OS-release       : 4.15.0-65-generic
machine          : x86_64
processor        : x86_64
byteorder        : little
LC_ALL           : None
LANG             : fr_FR.UTF-8
LOCALE           : fr_FR.UTF-8

pandas           : 1.0.1
numpy            : 1.18.1
pytz             : 2019.3
dateutil         : 2.8.1
pip              : 9.0.1
setuptools       : 39.0.1
Cython           : None
pytest           : None
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : None
html5lib         : 0.999999999
pymysql          : None
psycopg2         : None
jinja2           : None
IPython          : 7.12.0
pandas_datareader: None
bs4              : None
bottleneck       : None
fastparquet      : None
gcsfs            : None
lxml.etree       : None
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pytables         : None
pytest           : None
pyxlsb           : None
s3fs             : None
scipy            : 1.4.1
sqlalchemy       : None
tables           : None
tabulate         : None
xarray           : None
xlrd             : None
xlwt             : None
xlsxwriter       : None
numba            : None
</details>
