THRIFT-4698: add haskell hackage sdist target and fix cabal file
diff --git a/lib/hs/Makefile.am b/lib/hs/Makefile.am
index 3cd8b57..ba156a1 100644
--- a/lib/hs/Makefile.am
+++ b/lib/hs/Makefile.am
@@ -39,6 +39,9 @@
 clean-local:
 	$(CABAL) clean
 
+dist-local:
+	$(CABAL) sdist
+
 maintainer-clean-local:
 	$(CABAL) clean