Mir: Fix window/context creation order

Need to create the native window before creating the context as creating
the context creates the EGL surface.

src/mir_window.c

@@ -345,12 +345,6 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
                               const _GLFWctxconfig* ctxconfig,
                               const _GLFWfbconfig* fbconfig)
 {
-    if (ctxconfig->api != GLFW_NO_API)
-    {
-        if (!_glfwCreateContextEGL(window, ctxconfig, fbconfig))
-            return GLFW_FALSE;
-    }
-
     if (window->monitor)
     {
         GLFWvidmode mode;
@@ -377,6 +371,12 @@ int _glfwPlatformCreateWindow(_GLFWwindow* window,
     window->mir.window = mir_buffer_stream_get_egl_native_window(
                                    mir_surface_get_buffer_stream(window->mir.surface));
 
+    if (ctxconfig->api != GLFW_NO_API)
+    {
+        if (!_glfwCreateContextEGL(window, ctxconfig, fbconfig))
+            return GLFW_FALSE;
+    }
+
     return GLFW_TRUE;
 }