Add support with Go language.

sources_non_forked/vim-go/ftplugin/gomod.vim

@@ -0,0 +1,36 @@
+" gomod.vim: Vim filetype plugin for Go assembler.
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+" don't spam the user when Vim is started in Vi compatibility mode
+let s:cpo_save = &cpo
+set cpo&vim
+
+let b:undo_ftplugin = "setl fo< com< cms<
+      \ | exe 'au! vim-go-gomod-buffer * <buffer>'"
+
+setlocal formatoptions-=t
+
+setlocal comments=s1:/*,mb:*,ex:*/,://
+setlocal commentstring=//\ %s
+
+" Autocommands
+" ============================================================================
+
+augroup vim-go-gomod-buffer
+  autocmd! * <buffer>
+
+  autocmd BufWritePre <buffer> call go#auto#modfmt_autosave()
+  if go#util#has_job()
+    autocmd BufWritePost,FileChangedShellPost <buffer> call go#lsp#ModReload(resolve(expand('<afile>:p')))
+  endif
+augroup end
+
+" restore Vi compatibility settings
+let &cpo = s:cpo_save
+unlet s:cpo_save
+
+" vim: sw=2 ts=2 et