patch 8.2.0792: build failure with small features

Problem:    Build failure with small features.
Solution:   Add #ifdef.

src/popupwin.c

@@ -1757,6 +1757,7 @@ add_border_left_right_padding(win_T *wp)
     }
 }
 
+#ifdef FEAT_TERMINAL
 /*
  * Return TRUE if there is any popup window with a terminal buffer.
  */
@@ -1775,6 +1776,7 @@ popup_terminal_exists(void)
 		return TRUE;
     return FALSE;
 }
+#endif
 
 /*
  * popup_create({text}, {options})

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    792,
 /**/
     791,
 /**/