Question: Confusion between `-Wall` and `NamedFieldPuns`
I'm observing an interesting interaction between `-Wall` and `NamedFieldPuns`. Perhaps this is perfectly fine but wanted to double check.
I'm using:
```
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.6.5
```
For this program:
```haskell
module Test where
data F = F { foo :: Int }
bar :: F -> IO Int
bar f = do foo <- pure (foo f)
pure foo
```
I get:
```
$ ghc -c -Wall Test.hs
Test.hs:6:12: warning: [-Wname-shadowing]
This binding for ‘foo’ shadows the existing binding
defined at Test.hs:3:14
|
6 | bar f = do foo <- pure (foo f)
| ^^^
```
which makes perfect sense to me. However, if I add:
```haskell
{-# LANGUAGE NamedFieldPuns #-}
```
at the top, then the warning disappears, even though `-Wall` option is still present.
Is this the expected behavior? I don't understand how `NamedFieldPuns` interacts with shadowing here.
issue