Add syntax files from upstream vim repository

syntax/chaskell.vim

@@ -0,0 +1,18 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim syntax file
+" Language:	Haskell supporting c2hs binding hooks
+" Maintainer:	Armin Sander <armin@mindwalker.org>
+" Last Change:	2001 November 1
+"
+" 2001 November 1: Changed commands for sourcing haskell.vim
+
+" Enable binding hooks
+let b:hs_chs=1
+
+" Include standard Haskell highlighting
+runtime! syntax/haskell.vim
+
+" vim: ts=8
+
+endif