Explicit methods for Alternative Compose

Explicitly define some and many in Alternative instance for
Data.Functor.Compose

Implementation of https://github.com/haskell/core-libraries-committee/issues/181

libraries/base/changelog.md

@@ -11,6 +11,7 @@
   * Export List from Data.List ([CLC proposal #182](https://github.com/haskell/core-libraries-committee/issues/182)).
   * Deprecate `Data.List.NonEmpty.unzip` ([CLC proposal #86](https://github.com/haskell/core-libraries-committee/issues/86))
   * Fix exponent overflow/underflow bugs in the `Read` instances for `Float` and `Double` ([CLC proposal #192](https://github.com/haskell/core-libraries-committee/issues/192))
+  * Implement `many` and `some` methods of `instance Alternative (Compose f g)` explicitly. ([CLC proposal #181](https://github.com/haskell/core-libraries-committee/issues/181))
 
   * The functions `GHC.Exts.dataToTag#` and `GHC.Base.getTag` have had
     their types changed to the following:

libraries/base/src/Data/Functor/Compose.hs

@@ -147,6 +147,10 @@ instance (Alternative f, Applicative g) => Alternative (Compose f g) where
     empty = Compose empty
     (<|>) = coerce ((<|>) :: f (g a) -> f (g a) -> f (g a))
       :: forall a . Compose f g a -> Compose f g a -> Compose f g a
+    some = coerce (fmap sequenceA . some :: f (g a) -> f (g [a]))
+      :: forall a . Compose f g a -> Compose f g [a]
+    many = coerce (fmap sequenceA . many :: f (g a) -> f (g [a]))
+      :: forall a . Compose f g a -> Compose f g [a]
 
 -- | The deduction (via generativity) that if @g x :~: g y@ then @x :~: y@.
 --