Revert llvm support (takes too long to download)

ftplugin/llvm.vim

@@ -1,16 +0,0 @@
-if exists('g:polyglot_disabled') && index(g:polyglot_disabled, 'llvm') != -1
-  finish
-endif
-
-" Vim filetype plugin file
-" Language: LLVM Assembly
-" Maintainer: The LLVM team, http://llvm.org/
-
-if exists("b:did_ftplugin")
-  finish
-endif
-let b:did_ftplugin = 1
-
-setlocal softtabstop=2 shiftwidth=2
-setlocal expandtab
-setlocal comments+=:;