BUG: ValueError: cannot convert float NaN to integer - on dataframe.reset_index()
- [X] I have checked that this issue has not already been reported.

- [X] I have confirmed this bug exists on the latest version of pandas.

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

---



#### Code Sample

```python
import pandas as pd
df = pd.DataFrame(
    dict(c1=[10.], c2=['a'], c3=pd.to_datetime('2020-01-01')))
# Triggering conditions: multiindex with date, empty dataframe

# Multiindex without date works
df.set_index(['c1', 'c2']).head(0).reset_index()

# Regular index with date also works
df.set_index(['c3']).head(0).reset_index()

# Multiindex with date crashes...
df.set_index(['c2', 'c3']).head(0).reset_index()
# >> ValueError: cannot convert float NaN to integer
# This used to work on pandas 1.0.3, but breaks on pandas 1.1.0

# Though the error doesn't trigger if the dataframe is empty before
# calling set_index()
df.head(0).set_index(['c2', 'c3']).reset_index()

# I originally observed the bug in a groupby call
df.head(0).groupby(['c2', 'c3'])[['c1']].sum().reset_index()
# >> ValueError: cannot convert float NaN to integer
# This used to work on pandas 1.0.3, but breaks on pandas 1.1.0
```

#### Problem description

On pandas 1.1.0, I'm getting a ValueError exception when calling dataframe.reset_index() under the following conditions:
- Input dataframe is empty
- Multiindex from multiple columns, at least one of which is a datetime

The exception message is `ValueError: cannot convert float NaN to integer`.

Error trace:
```
Error
Traceback (most recent call last):
    df_out.reset_index()
  File "/Users/pec21/PycharmProjects/anp_voice_report/virtual/lib/python3.6/site-packages/pandas/core/frame.py", line 4848, in reset_index
    level_values = _maybe_casted_values(lev, lab)
  File "/Users/pec21/PycharmProjects/anp_voice_report/virtual/lib/python3.6/site-packages/pandas/core/frame.py", line 4782, in _maybe_casted_values
    fill_value, len(mask), dtype
  File "/Users/pec21/PycharmProjects/anp_voice_report/virtual/lib/python3.6/site-packages/pandas/core/dtypes/cast.py", line 1554, in construct_1d_arraylike_from_scalar
    subarr.fill(value)
ValueError: cannot convert float NaN to integer
```

This error didn't happen on pandas 1.0.3 and earlier. I haven't tested any intermediate releases, nor the master branch.


#### Expected Output

No exception is raised, returns an empty dataframe.

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

<details>

INSTALLED VERSIONS
------------------
commit           : d9fff2792bf16178d4e450fe7384244e50635733
python           : 3.6.6.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 18.6.0
Version          : Darwin Kernel Version 18.6.0: Thu Apr 25 23:16:27 PDT 2019; root:xnu-4903.261.4~2/RELEASE_X86_64
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : None
LOCALE           : en_GB.UTF-8
pandas           : 1.1.0
numpy            : 1.17.4
pytz             : 2019.3
dateutil         : 2.8.1
pip              : 20.0.2
setuptools       : 49.1.0
Cython           : None
pytest           : 5.3.4
hypothesis       : None
sphinx           : 2.3.1
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : 4.4.2
html5lib         : None
pymysql          : None
psycopg2         : 2.8.4 (dt dec pq3 ext lo64)
jinja2           : 2.10.3
IPython          : None
pandas_datareader: None
bs4              : 4.8.1
bottleneck       : None
fsspec           : None
fastparquet      : None
gcsfs            : None
matplotlib       : None
numexpr          : None
odfpy            : None
openpyxl         : 3.0.2
pandas_gbq       : None
pyarrow          : 0.15.1
pytables         : None
pyxlsb           : None
s3fs             : None
scipy            : 1.3.3
sqlalchemy       : 1.3.11
tables           : None
tabulate         : None
xarray           : None
xlrd             : 1.2.0
xlwt             : None
numba            : None

</details>
