egl: Factor some common terminate cleanup up to common code

It's a little difficult to see from the diff, but this is effectively
the same calling sequence as before, and more importantly it means the
backend only cleans up backend state rather than needing to call up to
the core.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18824>

src/egl/drivers/dri2/egl_dri2.c

@@ -1225,7 +1225,6 @@ dri2_display_release(_EGLDisplay *disp)
    if (!p_atomic_dec_zero(&dri2_dpy->ref_count))
       return;
 
-   _eglCleanupDisplay(disp);
    dri2_display_destroy(disp);
 }
 
@@ -1327,9 +1326,6 @@ dri2_egl_surface_free_local_buffers(struct dri2_egl_surface *dri2_surf)
 static EGLBoolean
 dri2_terminate(_EGLDisplay *disp)
 {
-   /* Release all non-current Context/Surfaces. */
-   _eglReleaseDisplayResources(disp);
-
    dri2_display_release(disp);
 
    return EGL_TRUE;

src/egl/drivers/wgl/egl_wgl.c

@@ -357,7 +357,6 @@ wgl_display_release(_EGLDisplay *disp)
    if (!p_atomic_dec_zero(&wgl_dpy->ref_count))
       return;
 
-   _eglCleanupDisplay(disp);
    wgl_display_destroy(disp);
 }
 
@@ -370,9 +369,6 @@ wgl_display_release(_EGLDisplay *disp)
 static EGLBoolean
 wgl_terminate(_EGLDisplay *disp)
 {
-   /* Release all non-current Context/Surfaces. */
-   _eglReleaseDisplayResources(disp);
-
    wgl_display_release(disp);
 
    return EGL_TRUE;

src/egl/main/eglapi.c

@@ -779,14 +779,9 @@ eglTerminate(EGLDisplay dpy)
       RETURN_EGL_ERROR(NULL, EGL_BAD_DISPLAY, EGL_FALSE);
 
    if (disp->Initialized) {
+      _eglReleaseDisplayResources(disp);
       disp->Driver->Terminate(disp);
-      /* do not reset disp->Driver */
-      disp->ClientAPIsString[0] = 0;
-      disp->Initialized = EGL_FALSE;
-
-      /* Reset blob cache funcs on terminate. */
-      disp->BlobCacheSet = NULL;
-      disp->BlobCacheGet = NULL;
+      _eglCleanupDisplay(disp);
    }
 
    simple_mtx_unlock(&disp->Mutex);

src/egl/main/egldisplay.c

@@ -370,7 +370,13 @@ _eglCleanupDisplay(_EGLDisplay *disp)
       disp->Configs = NULL;
    }
 
-   /* XXX incomplete */
+   /* do not reset disp->Driver */
+   disp->ClientAPIsString[0] = 0;
+   disp->Initialized = EGL_FALSE;
+
+   /* Reset blob cache funcs on terminate. */
+   disp->BlobCacheSet = NULL;
+   disp->BlobCacheGet = NULL;
 }