Enable closing stdin by pressing CTRL-D

This provides a way to use commands like :Git hash-object --stdin
without a PTY, which is not to say that there are any such commands that
one would actually want to use.  It also has debugging applications.

autoload/fugitive.vim

@@ -2303,15 +2303,26 @@ function! s:RunWait(state, job) abort
       if !exists('*jobwait')
         sleep 1m
       endif
+      if !get(a:state, 'closed')
         let peek = getchar(1)
         if peek != 0 && !(has('win32') && peek == 128)
           let c = getchar()
           let c = type(c) == type(0) ? nr2char(c) : c
+          if c ==# "\<C-D>"
+            let a:state.closed = 1
+            if type(a:job) ==# type(0)
+              call chanclose(a:job, 'stdin')
+            else
+              call ch_close_in(a:job)
+            endif
+          else
             call s:RunSend(a:job, c)
             if !a:state.pty
               echon c
             endif
           endif
+        endif
+      endif
     endwhile
     sleep 1m
     echo