patch 7.4.1611
Problem:    The versplit feature makes the code uneccessary complicated.
Solution:   Remove FEAT_VERTSPLIT, always support vertical splits when
            FEAT_WINDOWS is defined.
diff --git a/src/if_lua.c b/src/if_lua.c
index 1c8512f..8d76100 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -1177,7 +1177,7 @@
 	lua_pushinteger(L, w->w_cursor.lnum);
     else if (strncmp(s, "col", 3) == 0)
 	lua_pushinteger(L, w->w_cursor.col + 1);
-#ifdef FEAT_VERTSPLIT
+#ifdef FEAT_WINDOWS
     else if (strncmp(s, "width", 5) == 0)
 	lua_pushinteger(L, W_WIDTH(w));
 #endif
@@ -1220,7 +1220,7 @@
 	w->w_cursor.col = v - 1;
 	update_screen(VALID);
     }
-#ifdef FEAT_VERTSPLIT
+#ifdef FEAT_WINDOWS
     else if (strncmp(s, "width", 5) == 0)
     {
 	win_T *win = curwin;