Update

ftplugin/mir.vim

@@ -0,0 +1,17 @@
+if polyglot#init#is_disabled(expand('<sfile>:p'), 'llvm', 'ftplugin/mir.vim')
+  finish
+endif
+
+" Vim filetype plugin file
+" Language: LLVM Machine IR
+" 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+=:;
+