radeonsi: mark all bound shader buffer ranges as initialized

This should prevent cases when a buffer was incorrectly mapped without
synchronization just because this wasn't done.

Cc: 13.0 17.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>

src/gallium/drivers/radeonsi/si_descriptors.c

@@ -1227,6 +1227,9 @@ static void si_set_shader_buffers(struct pipe_context *ctx,
 		descs->dirty_mask |= 1u << slot;
 		sctx->descriptors_dirty |=
 			1u << si_shader_buffer_descriptors_idx(shader);
+
+		util_range_add(&buf->valid_buffer_range, sbuffer->buffer_offset,
+			       sbuffer->buffer_offset + sbuffer->buffer_size);
 	}
 }