Add syntax files from upstream vim repository

compiler/ghc.vim

@@ -0,0 +1,30 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim compiler file
+" Compiler:         GHC Haskell Compiler
+" Maintainer:       Daniel Campoverde <alx@sillybytes.net>
+" Latest Revision:  2016-11-29
+
+if exists("current_compiler")
+  finish
+endif
+let current_compiler = "ghc"
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+CompilerSet errorformat=
+    \%-G%.%#:\ build,
+    \%-G%.%#preprocessing\ library\ %.%#,
+    \%-G[%.%#]%.%#,
+    \%E%f:%l:%c:\ %m,
+    \%-G--%.%#
+
+if exists('g:compiler_ghc_ignore_unmatched_lines')
+  CompilerSet errorformat+=%-G%.%#
+endif
+
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+endif