postgres types int4, float8 are not supported

[yaitskov]

Hi,

parseStatement v0.6.0 fails for

SELECT  CAST(42 AS int4) from t;

SELECT  CAST(42 AS float8) from t;

but float8 is a valid type in postgres 9.5
https://www.postgresql.org/docs/9.5/datatype.html

[JakeWheat]

Thanks for the report, I would be happy to merge a pull request.
I didn't check the code, but it shouldn't even restrict the type name in a cast expression to known types, since you should also be able to cast to user defined types which have arbitrary names.