Add syntax files from upstream vim repository

compiler/cs.vim

@@ -0,0 +1,30 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim compiler file
+" Compiler:	Microsoft Visual Studio C#
+" Maintainer:	Zhou YiChao (broken.zhou@gmail.com)
+" Previous Maintainer:	Joseph H. Yao (hyao@sina.com)
+" Last Change:	2012 Apr 30
+
+if exists("current_compiler")
+  finish
+endif
+let current_compiler = "cs"
+let s:keepcpo= &cpo
+set cpo&vim
+
+if exists(":CompilerSet") != 2		" older Vim always used :setlocal
+  command -nargs=* CompilerSet setlocal <args>
+endif
+
+CompilerSet errorformat&
+CompilerSet errorformat+=%f(%l\\,%v):\ %t%*[^:]:\ %m,
+            \%trror%*[^:]:\ %m,
+            \%tarning%*[^:]:\ %m
+
+CompilerSet makeprg=csc\ %
+
+let &cpo = s:keepcpo
+unlet s:keepcpo
+
+endif