patch 8.2.0320: no Haiku support

Problem:    No Haiku support.
Solution:   Add support for Haiku. (Emir Sari, closes #5605)
diff --git a/src/gui.c b/src/gui.c
index 3f2a84c..4733bad 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -446,7 +446,8 @@
     gui.menu_width = 0;
 # endif
 #endif
-#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA))
+#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA) \
+	|| defined(FEAT_GUI_HAIKU))
     gui.toolbar_height = 0;
 #endif
 #if defined(FEAT_FOOTER) && defined(FEAT_GUI_MOTIF)
@@ -1371,10 +1372,11 @@
 	text_area_y += gui.tabline_height;
 #endif
 
-#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA))
+#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_ATHENA) \
+	|| defined(FEAT_GUI_HAIKU))
     if (vim_strchr(p_go, GO_TOOLBAR) != NULL)
     {
-# ifdef FEAT_GUI_ATHENA
+# if defined(FEAT_GUI_ATHENA) || defined(FEAT_GUI_HAIKU)
 	gui_mch_set_toolbar_pos(0, text_area_y,
 				gui.menu_width, gui.toolbar_height);
 # endif
@@ -1382,6 +1384,13 @@
     }
 #endif
 
+# if defined(FEAT_GUI_TABLINE) && defined(FEAT_GUI_HAIKU)
+    gui_mch_set_tabline_pos(0, text_area_y,
+    gui.menu_width, gui.tabline_height);
+    if (gui_has_tabline())
+	text_area_y += gui.tabline_height;
+#endif
+
     text_area_width = gui.num_cols * gui.char_width + gui.border_offset * 2;
     text_area_height = gui.num_rows * gui.char_height + gui.border_offset * 2;
 
@@ -1453,7 +1462,7 @@
 #  endif
 # endif
 # if defined(FEAT_GUI_TABLINE) && (defined(FEAT_GUI_MSWIN) \
-	|| defined(FEAT_GUI_MOTIF))
+	|| defined(FEAT_GUI_MOTIF) || defined(FEAT_GUI_HAIKU))
     if (gui_has_tabline())
 	base_height += gui.tabline_height;
 # endif
@@ -1496,6 +1505,10 @@
     new_pixel_height = 0;
     busy = TRUE;
 
+#ifdef FEAT_GUI_HAIKU
+    vim_lock_screen();
+#endif
+
     // Flush pending output before redrawing
     out_flush();
 
@@ -1518,6 +1531,10 @@
 	    || gui.num_rows != Rows || gui.num_cols != Columns)
 	shell_resized();
 
+#ifdef FEAT_GUI_HAIKU
+    vim_unlock_screen();
+#endif
+
     gui_update_scrollbars(TRUE);
     gui_update_cursor(FALSE, TRUE);
 #if defined(FEAT_XIM) && !defined(FEAT_GUI_GTK)
@@ -4254,9 +4271,10 @@
 		y += gui.menu_height;
 #endif
 
-#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_ATHENA))
+#if defined(FEAT_TOOLBAR) && (defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_ATHENA) \
+	|| defined(FEAT_GUI_HAIKU))
 	    if (vim_strchr(p_go, GO_TOOLBAR) != NULL)
-# ifdef FEAT_GUI_ATHENA
+# if defined(FEAT_GUI_ATHENA) || defined(FEAT_GUI_HAIKU)
 		y += gui.toolbar_height;
 # else
 #  ifdef FEAT_GUI_MSWIN
@@ -4265,7 +4283,7 @@
 # endif
 #endif
 
-#if defined(FEAT_GUI_TABLINE) && defined(FEAT_GUI_MSWIN)
+#if defined(FEAT_GUI_TABLINE) && defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_HAIKU)
 	    if (gui_has_tabline())
 		y += gui.tabline_height;
 #endif
@@ -5035,10 +5053,11 @@
 }
 
 #if ((defined(FEAT_GUI_X11) || defined(FEAT_GUI_GTK) \
-	    || defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_PHOTON)) \
+	    || defined(FEAT_GUI_MSWIN) || defined(FEAT_GUI_PHOTON) \
+	    || defined(FEAT_GUI_HAIKU)) \
 	    && defined(FEAT_TOOLBAR)) || defined(PROTO)
 /*
- * This is shared between Athena, Motif and GTK.
+ * This is shared between Athena, Haiku, Motif, and GTK.
  */
 
 /*