ERR: frame construction with all scalars doesn't raise when columns are provided

xref #9456 

[39] should raise.

```
In [38]: pd.DataFrame({'a':0.1})
ValueError: If using all scalar values, you must pass an index

In [39]: pd.DataFrame({'a':0.1}, columns=['b'])
Out[39]:
Empty DataFrame
Columns: [b]
Index: []
```
