Warning about redundant bang patterns
Motivation
I have seen pattern matches like this one in Haskell code:
f !(Cons a b c) = ...The bang pattern on Cons is unnecessary since if you pattern match on Cons
the argument is evaluated to weak head normal form, anyway.
The programmer might expect that ! performs a deep evaluation
or just hopes that random addition of ! to some arguments
may improve speed or memory consumption.
Proposal
Please add a warning for redundant bang patterns and add it to -Wall.