patch 8.1.1400: using global pointer for tab-local popups is clumsy

Problem:    Using global pointer for tab-local popups is clumsy.
Solution:   Use the pointer in tabpage_T.
diff --git a/src/window.c b/src/window.c
index ffff756..bc8dac0 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1371,7 +1371,7 @@
     for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
 	if (wp == win)
 	    return TRUE;
-    for (wp = first_tab_popupwin; wp != NULL; wp = wp->w_next)
+    for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
 	if (wp == win)
 	    return TRUE;
 #endif
@@ -3673,13 +3673,8 @@
     {
 	win_T *wp;
 
-	for (;;)
-	{
-	    wp = tp == curtab ? first_tab_popupwin : tp->tp_first_popupwin;
-	    if (wp == NULL)
-		break;
-	    popup_close_tabpage(tp, wp->w_id);
-	}
+	while (tp->tp_first_popupwin != NULL)
+	    popup_close_tabpage(tp, tp->tp_first_popupwin->w_id);
     }
 #endif
     for (idx = 0; idx < SNAP_COUNT; ++idx)
@@ -3973,10 +3968,6 @@
     tp->tp_prevwin = prevwin;
     tp->tp_firstwin = firstwin;
     tp->tp_lastwin = lastwin;
-#ifdef FEAT_TEXT_PROP
-    tp->tp_first_popupwin = first_tab_popupwin;
-    first_tab_popupwin = NULL;
-#endif
     tp->tp_old_Rows = Rows;
     tp->tp_old_Columns = Columns;
     firstwin = NULL;
@@ -4004,9 +3995,6 @@
     firstwin = tp->tp_firstwin;
     lastwin = tp->tp_lastwin;
     topframe = tp->tp_topframe;
-#ifdef FEAT_TEXT_PROP
-    first_tab_popupwin = tp->tp_first_popupwin;
-#endif
 
     /* We would like doing the TabEnter event first, but we don't have a
      * valid current window yet, which may break some commands.
@@ -6513,15 +6501,9 @@
 	{
 	    curtab->tp_firstwin = firstwin;
 	    curtab->tp_lastwin = lastwin;
-#ifdef FEAT_TEXT_PROP
-	    curtab->tp_first_popupwin = first_tab_popupwin ;
-#endif
 	    curtab = tp;
 	    firstwin = curtab->tp_firstwin;
 	    lastwin = curtab->tp_lastwin;
-#ifdef FEAT_TEXT_PROP
-	    first_tab_popupwin = curtab->tp_first_popupwin;
-#endif
 	}
 	else
 	    goto_tabpage_tp(tp, FALSE, FALSE);
@@ -6550,15 +6532,9 @@
 	{
 	    curtab->tp_firstwin = firstwin;
 	    curtab->tp_lastwin = lastwin;
-#ifdef FEAT_TEXT_PROP
-	    curtab->tp_first_popupwin = first_tab_popupwin ;
-#endif
 	    curtab = save_curtab;
 	    firstwin = curtab->tp_firstwin;
 	    lastwin = curtab->tp_lastwin;
-#ifdef FEAT_TEXT_PROP
-	    first_tab_popupwin = curtab->tp_first_popupwin;
-#endif
 	}
 	else
 	    goto_tabpage_tp(save_curtab, FALSE, FALSE);