patch 8.0.1538: popupmenu is too far left when completion is long

Problem:    Popupmenu is too far left when completion is long. (Linwei)
Solution:   Adjust column computations. (Hirohito Higashi, closes #2661)
diff --git a/src/popupmnu.c b/src/popupmnu.c
index dfdcca0..6ac121d 100644
--- a/src/popupmnu.c
+++ b/src/popupmnu.c
@@ -253,7 +253,7 @@
 		/* align right pum edge with "col" */
 #ifdef FEAT_RIGHTLEFT
 		if (curwin->w_p_rl
-			&& col < max_width + pum_scrollbar + 1)
+			&& W_ENDCOL(curwin) < max_width + pum_scrollbar + 1)
 		{
 		    pum_col = col + max_width + pum_scrollbar + 1;
 		    if (pum_col >= Columns)
@@ -262,7 +262,7 @@
 		else if (!curwin->w_p_rl)
 #endif
 		{
-		    if (col > Columns - max_width - pum_scrollbar)
+		    if (curwin->w_wincol > Columns - max_width - pum_scrollbar)
 		    {
 			pum_col = Columns - max_width - pum_scrollbar;
 			if (pum_col < 0)