egl/dri2: rework dri2_egl_display::extensions storage

Remove the error prone fixed size array.
While we're here also rename to loader_extensions like in the GLX code.

v2: Rebase. Keep image_loader_extension within the wayland_drm
dri2_loader_extensions list.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 5b6fe25..59dd3e8 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -685,7 +685,7 @@
    if (dri2_dpy->image_driver) {
       dri2_dpy->dri_screen =
          dri2_dpy->image_driver->createNewScreen2(0, dri2_dpy->fd,
-                                                  dri2_dpy->extensions,
+                                                  dri2_dpy->loader_extensions,
                                                   dri2_dpy->driver_extensions,
                                                   &dri2_dpy->driver_configs,
                                                   disp);
@@ -693,25 +693,25 @@
       if (dri2_dpy->dri2->base.version >= 4) {
          dri2_dpy->dri_screen =
             dri2_dpy->dri2->createNewScreen2(0, dri2_dpy->fd,
-                                             dri2_dpy->extensions,
+                                             dri2_dpy->loader_extensions,
                                              dri2_dpy->driver_extensions,
                                              &dri2_dpy->driver_configs, disp);
       } else {
          dri2_dpy->dri_screen =
             dri2_dpy->dri2->createNewScreen(0, dri2_dpy->fd,
-                                            dri2_dpy->extensions,
+                                            dri2_dpy->loader_extensions,
                                             &dri2_dpy->driver_configs, disp);
       }
    } else {
       assert(dri2_dpy->swrast);
       if (dri2_dpy->swrast->base.version >= 4) {
          dri2_dpy->dri_screen =
-            dri2_dpy->swrast->createNewScreen2(0, dri2_dpy->extensions,
+            dri2_dpy->swrast->createNewScreen2(0, dri2_dpy->loader_extensions,
                                                dri2_dpy->driver_extensions,
                                                &dri2_dpy->driver_configs, disp);
       } else {
          dri2_dpy->dri_screen =
-            dri2_dpy->swrast->createNewScreen(0, dri2_dpy->extensions,
+            dri2_dpy->swrast->createNewScreen(0, dri2_dpy->loader_extensions,
                                               &dri2_dpy->driver_configs, disp);
       }
    }