DsRuleIgnoredDueToConstructor -> 828

[PPKFS]

[BinderDavid]

module T13290 where

data Foo = Bar Int Char | Baz Char

{-# RULES
"BarBaz" Bar 0 'a' = Baz 'b'
 #-}

results in

T13290.hs:6:1: warning: [GHC-00828]
    A constructor, Bar, appears as outermost match in RULE lhs.
    This rule will be ignored.

This warning was introduced in this issue:
https://gitlab.haskell.org/ghc/ghc/-/issues/13290