Add checked versions of 'resize', 'truncateB', and 'fromIntegral'

[martijnbastiaan]

Depending on the type 'resize', 'truncateB', and 'fromIntegral' either
yield an XException or silently perform wrap-around if its argument does
not fit in the resulting type's bounds. The added functions check the
bound condition and fail with an error call if the condition is
violated. They do not affect HDL generation.

Useful in cases where runtime behavior should ensure that and out of
bound or wrap around should not occur and users want their code to fail
hard if this invariant is ever violated.

[martijnbastiaan]

@christiaanb Concerning the offline chat: I do agree that parsing is better than validating, but:

• The resize / truncateB functions are already here and "unsafe".
• Unless we add type level information to Bounded (or another class) we can't write type safe conversion functions
• This would have, if used, made my debug run over at our client a matter of minutes instead of hours.

In short, I'm very much for adding this to clash-prelude