patch 8.2.1264: terminal getwinpos() test is a bit flaky

Problem:    Terminal getwinpos() test is a bit flaky.
Solution:   Call getwinpos() a bit later.

src/testdir/test_terminal3.vim

@@ -527,11 +527,9 @@ func Test_terminal_getwinpos()
   wincmd j
   set splitright
 
-  call writefile([
+  let buf = RunVimInTerminal('', {'cols': 60})
-	\ 'echo getwinpos()',
+  call TermWait(buf, 100)
-	\ ], 'XTest_getwinpos')
+  call term_sendkeys(buf, ":echo getwinpos(500)\<CR>")
-  let buf = RunVimInTerminal('-S XTest_getwinpos', {'cols': 60})
-  call TermWait(buf)
 
   " Find the output of getwinpos() in the bottom line.
   let rows = term_getsize(buf)[0]
@@ -557,7 +555,6 @@ func Test_terminal_getwinpos()
   call TermWait(buf)
   call term_sendkeys(buf, ":q\<CR>")
   call StopVimInTerminal(buf)
-  call delete('XTest_getwinpos')
   exe buf . 'bwipe!'
   set splitright&
   only!

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1264,
 /**/
     1263,
 /**/