patch 9.0.0446: message window may be positioned too low

Problem:    Message window may be positioned too low.
Solution:   Compute cmdline_row before computing the position.

src/popupwin.c

@@ -1301,9 +1301,14 @@ popup_adjust_position(win_T *wp)
 		wp->w_winrow = Rows - 1;
 	}
 	if (wp->w_popup_pos == POPPOS_BOTTOM)
-	    // assume that each buffer line takes one screen line
+	{
+	    // Assume that each buffer line takes one screen line, and one line
+	    // for the top border.  First make sure cmdline_row is valid,
+	    // calling update_screen() will set it only later.
+	    compute_cmdrow();
 	    wp->w_winrow = MAX(cmdline_row
 				    - wp->w_buffer->b_ml.ml_line_count - 1, 0);
+	}
 
 	if (!use_wantcol)
 	    center_hor = TRUE;

src/testdir/dumps/Test_echowindow_5.dump

@@ -0,0 +1,8 @@
+>s+0&#ffffff0|o|m|e| |t|e|x|t| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|═+0#e000002&@74
+|m|e|s@1|a|g|e| @67
+|o+0#0000000&|n|e| @71
+|t|w|o| @53|1|,|1| @10|A|l@1| 

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    446,
 /**/
     445,
 /**/