patch 8.1.1511: matches in a popup window are not displayed properly

Problem:    Matches in a popup window are not displayed properly.
Solution:   Do display matches in a popup window. (closes #4517)
diff --git a/src/screen.c b/src/screen.c
index 0a93f86..fae9fe7 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -3957,12 +3957,11 @@
     /*
      * Handle highlighting the last used search pattern and matches.
      * Do this for both search_hl and the match list.
-     * Not in a popup window.
+     * Do not use search_hl in a popup window.
      */
     cur = wp->w_match_head;
-    shl_flag = FALSE;
-    while ((cur != NULL || shl_flag == FALSE) && !number_only
-					   && !(screen_line_flags & SLF_POPUP))
+    shl_flag = (screen_line_flags & SLF_POPUP);
+    while ((cur != NULL || shl_flag == FALSE) && !number_only)
     {
 	if (shl_flag == FALSE)
 	{
@@ -4438,7 +4437,7 @@
 		 */
 		v = (long)(ptr - line);
 		cur = wp->w_match_head;
-		shl_flag = FALSE;
+		shl_flag = (screen_line_flags & SLF_POPUP);
 		while (cur != NULL || shl_flag == FALSE)
 		{
 		    if (shl_flag == FALSE