Bad error message when `!` is used without BangPatterns extension

For

f :: a -> a
f !x = x

ghc-HEAD gives

P.hs:22:1: error:
    The type signature for ‘f’ lacks an accompanying binding
   |
22 | f :: a -> a
   | ^

Here ghc should suggest BangPatterns extension.

Trac metadata

Trac field	Value
Version	8.5
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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