feat(3p/haskellPackages): port in patches from xanthous

Add a few relatively uncontroversial patches to fix some broken packages
that I had developed for xanthous to the top-level third_party tree, so
they can be reused by other people in the monorepo

Change-Id: I68740477bda278c5dcc123080029ee4bd2cae37a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/740
Reviewed-by: Profpatsch <mail@profpatsch.de>
Reviewed-by: tazjin <mail@tazj.in>

third_party/haskell_overlay/patches/generic-arbitrary-export-garbitrary.patch

@@ -0,0 +1,12 @@
+diff --git a/src/Test/QuickCheck/Arbitrary/Generic.hs b/src/Test/QuickCheck/Arbitrary/Generic.hs
+index fed6ab3..91f59f1 100644
+--- a/src/Test/QuickCheck/Arbitrary/Generic.hs
++++ b/src/Test/QuickCheck/Arbitrary/Generic.hs
+@@ -23,6 +23,7 @@ The generated 'arbitrary' method is equivalent to
+ 
+ module Test.QuickCheck.Arbitrary.Generic
+   ( Arbitrary(..)
++  , GArbitrary
+   , genericArbitrary
+   , genericShrink
+   ) where