patch 8.2.2647: terminal test sometimes hangs

Problem:    Terminal test sometimes hangs.
Solution:   Wait for the shell to display a prompt.

src/testdir/test_terminal.vim

@@ -889,6 +889,8 @@ endfunc
 
 func TerminalTmap(remap)
   let buf = Run_shell_in_terminal({})
+  " Wait for the shell to display a prompt
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
   call assert_equal('t', mode())
 
   if a:remap

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2647,
 /**/
     2646,
 /**/