Sylvain Henry authored Feb 05, 2019 and Marge Bot committed Feb 08, 2019

* GHC now performs constant folding on bit operations like (.|.) so we
use them and we remove the misleading comment

* we use Word8 instead of Int and we remove the useless conversion to
Int32. Hopefully future releases of GHC could transform the big case in
`charType` into a value table indexing instead of a jump table. Word8
would make the table smaller.

* we use INLINABLE pragma instead of INLINE on `is_ctype`: in my test,
the latter *prevents* `is_ctype` to be inlined because `charType` is
inlined into `is_ctype` (to call charType`s worker on the unboxed Char
directly).