[nvim] use `is#` instead of `is` for comparisons

nvim/lib/editing.vim

@@ -62,7 +62,7 @@ set foldmethod=marker
 " Mappings {{{
 
   " arguably one of the most useful mappings
-  nnoremap <silent><expr> <CR> empty(&buftype) ? ":w\<CR>" : "\<CR>"
+  nnoremap <silent><expr> <CR> &buftype is# '' ? ":w\<CR>" : "\<CR>"
 
   " stay in the Visual mode when using shift commands
   xnoremap < <gv

nvim/lib/interface.vim

@@ -48,11 +48,11 @@ endif
       let l:cmd = a:cmd
       if &modified
         let l:answer = confirm("Save changes?", "&Yes\n&No\n&Cancel")
-        if l:answer is 1      " Yes
+        if l:answer is# 1      " Yes
           write
-        elseif l:answer is 2  " No
+        elseif l:answer is# 2  " No
           let l:cmd .= '!'
-        else                  " Cancel/Other
+        else                   " Cancel/Other
           return
         endif
       endif